Environmental Engineering (EE) - Power supply interface at the input of Information and Communication Technology (ICT) equipment - Part 3: Up to 400 V Direct Current (DC)

The present document contains requirements and measurements methods for the physical interface "A3" that is situated
between the power supply system(s) and the power consuming ICT equipment:
• the nominal voltage at power interface "A3" of ICT equipment defined in the present document is DC voltage up
to 400 V;
• the output performance of the power equipment including the cable network at the interface "A3";
• the input of the ICT equipment connected to interface "A3".
The DC power can be supplied by a DC output power system e.g. via on-grid AC rectifiers, from DC/DC converters in
solar systems, fuel cells, standby generators including a battery backup.
The present document aims at providing compatibility at interface "A3" between the power supply equipment and different
ICT equipment (including/monitoring, cooling system, etc.) connected to the same power supply.
The requirements are defined for the purpose of the present document:
• to identify a power supply system with the same characteristics for all ICT equipment defined in the area of
application; the area of application may be any location where the interface "A3" is used i.e.
telecommunication centres, Radio Base Stations, datacentres and customer premises;
• to facilitate interworking of different loads;
• to facilitate the standardization of power supply systems for ICT equipment;
• to facilitate the installation, operation and maintenance in the same network of ICT equipment and systems
from different origins;
• to secure robustness against temporary voltage deviations and transients during abnormal conditions.
General requirements for safety and EMC are out of the scope of the present document series unless specific
requirement not defined in existing safety or EMC standards.

Okoljski inženiring (EE) - Napajalni vmesnik na vhodu v informacijsko in komunikacijsko tehnološko (ICT) opremo - 3. del: Enosmerno napajanje (DC) do 400 V

General Information

Status
Published
Public Enquiry End Date
29-Jun-2021
Publication Date
21-Jul-2021
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
21-Jul-2021
Due Date
25-Sep-2021
Completion Date
22-Jul-2021

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SLOVENSKI STANDARD
SIST EN 300 132-3 V2.2.1:2021
01-september-2021
Okoljski inženiring (EE) - Napajalni vmesnik na vhodu v informacijsko in
komunikacijsko tehnološko (ICT) opremo - 3. del: Enosmerno napajanje (DC) do
400 V

Environmental Engineering (EE) - Power supply interface at the input of Information and

Communication Technology (ICT) equipment - Part 3: Up to 400 V Direct Current (DC)

Ta slovenski standard je istoveten z: ETSI EN 300 132-3 V2.2.1 (2021-07)
ICS:
19.040 Preskušanje v zvezi z Environmental testing
okoljem
35.200 Vmesniška in povezovalna Interface and interconnection
oprema equipment
SIST EN 300 132-3 V2.2.1:2021 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST EN 300 132-3 V2.2.1:2021
---------------------- Page: 2 ----------------------
SIST EN 300 132-3 V2.2.1:2021
ETSI EN 300 132-3 V2.2.1 (2021-07)
EUROPEAN STANDARD
Environmental Engineering (EE);
Power supply interface at the input of Information and
Communication Technology (ICT) equipment;
Part 3: Up to 400 V Direct Current (DC)
---------------------- Page: 3 ----------------------
SIST EN 300 132-3 V2.2.1:2021
2 ETSI EN 300 132-3 V2.2.1 (2021-07)
Reference
REN/EE-0265
Keywords
environment, interface, power supply
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE
Tel.: +33 4 92 94 42 00 Fax: +33 4 93 65 47 16
Siret N° 348 623 562 00017 - APE 7112B
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° w061004871
Important notice
The present document can be downloaded from:
http://www.etsi.org/standards-search

The present document may be made available in electronic versions and/or in print. The content of any electronic and/or

print versions of the present document shall not be modified without the prior written authorization of ETSI. In case of any

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deliverable is the one made publicly available in PDF format at www.etsi.org/deliver.

Users of the present document should be aware that the document may be subject to revision or change of status.

Information on the current status of this and other ETSI documents is available at

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Notice of disclaimer & limitation of liability

The information provided in the present deliverable is directed solely to professionals who have the appropriate degree of

experience to understand and interpret its content in accordance with generally accepted engineering or

other professional standard and applicable regulations.

No recommendation as to products and services or vendors is made or should be implied.

In no event shall ETSI be held liable for loss of profits or any other incidental or consequential damages.

Any software contained in this deliverable is provided "AS IS" with no warranties, express or implied, including but not

limited to, the warranties of merchantability, fitness for a particular purpose and non-infringement of intellectual property

rights and ETSI shall not be held liable in any event for any damages whatsoever (including, without limitation, damages

for loss of profits, business interruption, loss of information, or any other pecuniary loss) arising out of or related to the use

of or inability to use the software.
Copyright Notification

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The content of the PDF version shall not be modified without the written authorization of ETSI.

The copyright and the foregoing restriction extend to reproduction in all media.
© ETSI 2021.
All rights reserved.
ETSI
---------------------- Page: 4 ----------------------
SIST EN 300 132-3 V2.2.1:2021
3 ETSI EN 300 132-3 V2.2.1 (2021-07)
Contents

Intellectual Property Rights ................................................................................................................................ 5

Foreword ............................................................................................................................................................. 5

Modal verbs terminology .................................................................................................................................... 6

1 Scope ........................................................................................................................................................ 7

2 References ................................................................................................................................................ 7

2.1 Normative references ......................................................................................................................................... 7

2.2 Informative references ........................................................................................................................................ 8

3 Definition of terms, symbols and abbreviations ....................................................................................... 8

3.1 Terms .................................................................................................................................................................. 8

3.2 Symbols .............................................................................................................................................................. 9

3.3 Abbreviations ................................................................................................................................................... 10

4 Power interface "A3" .............................................................................................................................. 10

5 DC interface requirements ...................................................................................................................... 11

5.0 General ............................................................................................................................................................. 11

5.1 Nominal voltage ............................................................................................................................................... 11

5.2 Normal service voltage range at interface "A3" ............................................................................................... 11

5.3 Normal operating voltage range at interface "A3" ........................................................................................... 12

5.4 Reference test voltage (U ) at interface "A3" ................................................................................................... 12

5.5 Abnormal service voltage ranges at interface "A3" .......................................................................................... 12

6 Abnormal conditions: Voltage variations, voltage dips, short interruptions and voltage surges at

interface "A3" ......................................................................................................................................... 13

6.0 General ............................................................................................................................................................. 13

6.1 Voltage variations............................................................................................................................................. 13

6.2 Voltage dips...................................................................................................................................................... 14

6.3 Short interruptions ............................................................................................................................................ 14

6.4 Voltage surges .................................................................................................................................................. 15

7 DC Supply protection ............................................................................................................................. 16

8 Maximum steady state current I , in the normal service voltage range ................................................. 16

9 Inrush current on connection to interface "A3" ...................................................................................... 17

9.1 Limits ............................................................................................................................................................... 17

9.2 Measurements ................................................................................................................................................... 18

10 Installation and Cabling, Earthing and Bonding .................................................................................... 19

11 Electrical Safety requirements ................................................................................................................ 19

12 EMC requirements at the input of ICT equipment ................................................................................. 20

Annex A (informative): Power supply considerations ......................................................................... 21

Annex B (informative): Identification of interface "A3" .................................................................... 22

Annex C (informative): Calculation of the extreme DC voltage range at interface "A3" ............... 23

Annex D (informative): Guide for defining inrush current energy, measuring inrush current

and test generator peak inrush current drive capability............................ 24

D.0 General ................................................................................................................................................... 24

D.1 Measurement .......................................................................................................................................... 24

D.2 Test generator peak inrush current drive capability ............................................................................... 25

D.3 Example of inrush current waveform ..................................................................................................... 25

ETSI
---------------------- Page: 5 ----------------------
SIST EN 300 132-3 V2.2.1:2021
4 ETSI EN 300 132-3 V2.2.1 (2021-07)

Annex E (informative): Dimensioning of over-current protective devices ........................................ 27

Annex F (informative): Details of the voltage transient measurement in the most common

case of distribution and protective devices .................................................. 28

Annex G (informative): Diagram of voltage ranges and values at the interface "A3" .................... 30

History .............................................................................................................................................................. 31

ETSI
---------------------- Page: 6 ----------------------
SIST EN 300 132-3 V2.2.1:2021
5 ETSI EN 300 132-3 V2.2.1 (2021-07)
Intellectual Property Rights
Essential patents

IPRs essential or potentially essential to normative deliverables may have been declared to ETSI. The declarations

pertaining to these essential IPRs, if any, are publicly available for ETSI members and non-members, and can be

found in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to

ETSI in respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the

ETSI Web server (https://ipr.etsi.org/).

Pursuant to the ETSI Directives including the ETSI IPR Policy, no investigation regarding the essentiality of IPRs,

including IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not

referenced in ETSI SR 000 314 (or the updates on the ETSI Web server) which are, or may be, or may become,

essential to the present document.
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ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no

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not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks.

DECT™, PLUGTESTS™, UMTS™ and the ETSI logo are trademarks of ETSI registered for the benefit of its

Members. 3GPP™ and LTE™ are trademarks of ETSI registered for the benefit of its Members and of the 3GPP

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Foreword

This European Standard (EN) has been produced by ETSI Technical Committee Environmental Engineering (EE).

The present document concerns the requirements for the interface between Information and Communication

Technology (ICT) equipment and its power supply. It includes requirements relating to its stability and measurement.

Various other references and detailed measurement and test arrangements are contained in informative annexes.

The introduced interface up to 400 V Direct Current (DC) is considering power consumption increase and equipment

power density increase in order to get higher energy efficiency with less material than with low voltage -48 VDC or

permanent AC powering solution.

The up to 400 VDC interface could also simplify the use of renewable energy source with DC output such as

photovoltaic generator.

The present document is part 3 of a multi-part deliverable covering Environmental Engineering (EE); Power supply

interface at the input to Information and Communication Technology ICT equipment, as identified below:

Part 1: "Alternating Current (AC)";
Part 2: "-48 V Direct Current (DC)";
Part 3: "Up to 400 V Direct Current (DC)";
Part 4: "Up to 400 V Direct Current (DC) and Alternating Current (AC)".
ETSI
---------------------- Page: 7 ----------------------
SIST EN 300 132-3 V2.2.1:2021
6 ETSI EN 300 132-3 V2.2.1 (2021-07)
National transposition dates
Date of adoption of this EN: 30 June 2021
Date of latest announcement of this EN (doa): 30 September 2021
Date of latest publication of new National Standard
or endorsement of this EN (dop/e): 31 March 2022
Date of withdrawal of any conflicting National Standard (dow): 31 March 2022
Modal verbs terminology

In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and

"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of

provisions).

"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.

ETSI
---------------------- Page: 8 ----------------------
SIST EN 300 132-3 V2.2.1:2021
7 ETSI EN 300 132-3 V2.2.1 (2021-07)
1 Scope

The present document contains requirements and measurements methods for the physical interface "A3" that is situated

between the power supply system(s) and the power consuming ICT equipment:

• the nominal voltage at power interface "A3" of ICT equipment defined in the present document is DC voltage up

to 400 V;

• the output performance of the power equipment including the cable network at the interface "A3";

• the input of the ICT equipment connected to interface "A3".

The DC power can be supplied by a DC output power system e.g. via on-grid AC rectifiers, from DC/DC converters in

solar systems, fuel cells, standby generators including a battery backup.

The present document aims at providing compatibility at interface "A3" between the power supply equipment and different

ICT equipment (including/monitoring, cooling system, etc.) connected to the same power supply.

The requirements are defined for the purpose of the present document:

• to identify a power supply system with the same characteristics for all ICT equipment defined in the area of

application; the area of application may be any location where the interface "A3" is used i.e.

telecommunication centres, Radio Base Stations, datacentres and customer premises;

• to facilitate interworking of different loads;
• to facilitate the standardization of power supply systems for ICT equipment;

• to facilitate the installation, operation and maintenance in the same network of ICT equipment and systems

from different origins;

• to secure robustness against temporary voltage deviations and transients during abnormal conditions.

General requirements for safety and EMC are out of the scope of the present document series unless specific

requirement not defined in existing safety or EMC standards.
2 References
2.1 Normative references

References are either specific (identified by date of publication and/or edition number or version number) or

non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the

referenced document (including any amendments) applies.

Referenced documents which are not found to be publicly available in the expected location might be found at

https://docbox.etsi.org/Reference.

NOTE: While any hyperlinks included in the present clause were valid at the time of publication, ETSI cannot

guarantee their long term validity.

The following referenced documents are necessary for the application of the present document.

[1] IEC 60947-2: "Low-voltage switchgear and controlgear - Part 2: Circuit-breakers".

[2] IEC 60269-1: "Low-voltage fuses - Part 1: General requirements".

[3] IEC 61000-4-5: "Electromagnetic compatibility (EMC) - Part 4-5: Testing and measurement

techniques - Surge immunity test".
ETSI
---------------------- Page: 9 ----------------------
SIST EN 300 132-3 V2.2.1:2021
8 ETSI EN 300 132-3 V2.2.1 (2021-07)

[4] IEC 61000-4-29: "Electromagnetic compatibility (EMC) - Part 4-29: Testing and measurement

techniques - Voltage dips, short interruptions and voltage variations on d.c. input power port

immunity tests".

[5] IEC 60898-2: "Electrical accessories - Circuit-breakers for overcurrent protection for household

and similar installations - Part 2: Circuit-breakers for AC and DC operation".

[6] ETSI EN 301 605 (V1.1.1) (2013): "Environmental Engineering (EE); Earthing and bonding of

400 VDC data and telecom (ICT) equipment".

[7] Recommendation ITU-T L.1207 (2018): "Progressive migration of telecommunication/information

and communication technology site to 400 VDC sources and distribution".

[8] IEC 60364-4-41: "Low voltage electrical installations - Part 4-41: Protection for safety - Protection

against electric shock".

[9] EN 60445: "Basic and safety principle for man-machine interface, marking and identification-

Identification of equipment terminals, conductor terminations and conductors". (Produced by

CENELEC).

[10] Recommendation ITU-T L.1203 (2016): "Colour and marking identification of up to 400 VDC

power distribution for information and communication technology systems".
2.2 Informative references

References are either specific (identified by date of publication and/or edition number or version number) or

non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the

referenced document (including any amendments) applies.

NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee

their long term validity.

The following referenced documents are not necessary for the application of the present document but they assist the

user with regard to a particular subject area.

[i.1] ETSI EN 300 132-2: "Environmental Engineering (EE); Power supply interface at the input of

Information and Communication Technology (ICT) equipment; Part 2: -48 V Direct Current

(DC)".

[i.2] IEC 60050-601: "International Electrotechnical Vocabulary. Chapter 601: Generation,

transmission and distribution of electricity - General".

[i.3] ETSI EN 300 386: "Electromagnetic compatibility and Radio spectrum Matters (ERM);

Telecommunication network equipment; ElectroMagnetic Compatibility (EMC) requirements".

[i.4] EN 62368-1: "Audio/video, information and communication technology equipment - Part 1: Safety

requirements". (Produced by CENELEC).
3 Definition of terms, symbols and abbreviations
3.1 Terms
For the purposes of the present document, the following terms apply:

abnormal service voltage ranges: steady-state voltage ranges over which the ICT equipment will not be expected to

maintain normal service but will survive undamaged
area of application: any location where the interface "A3" is used

NOTE: I.e. telecommunication centres, Radio Base Stations, datacentres and customer premises.

ETSI
---------------------- Page: 10 ----------------------
SIST EN 300 132-3 V2.2.1:2021
9 ETSI EN 300 132-3 V2.2.1 (2021-07)
customer premises: any location which is the sole responsibility of the customer

dual feeding system: independent power systems i.e. two separate power sources (A+B)

high-ohmic distribution system: distribution system in which the equipment is connected separately to the battery

with added impedance

NOTE 1: The high impedance can be achieved with long cables and in some cases additional resistors are installed.

NOTE 2: With this distribution the undervoltage effects of fuse blowing transients are reduced on other equipment

connected to the battery.
ICT equipment: telecommunication or datacommunication equipment

independent power distribution: redundant power distribution i.e. dual feeders (A+B) from two separate power

sources (A+B) or a single power source

NOTE: Equipment having two power feeds is fitted with OR-ing devices or separate power supply units.

interface "A3": power interface at the input terminals of ICT, physical point, at which power supply is connected in

order to operate the ICT equipment
load unit: power consuming equipment, that is part of a system block

nominal voltage: value of the voltage by which the electrical installation or part of the electrical installation is

designated and identified

NOTE: This definition is based on nominal voltage defined in IEC 60050-601 [i.2].

normal operating condition: typical environmental and powering conditions for operation of ICT equipment, power

supply, power distribution and battery

normal operating voltage: typical value of the voltage at "A3" interface within the normal operating voltage range

normal operating voltage range: voltage range at "A3" interface where the system operates most of the time, e.g. in

general linked to battery floating voltage

normal service: service mode where ICT equipment operates within its specification

normal service voltage range: range of the steady-state voltage at the "A3" interface over which the equipment will

maintain normal service

NOTE: In general this wider than the normal operating voltage range as it includes a part of the battery discharge

voltage range.

operating voltage: value of the voltage under normal conditions, at a given instant and a given point ("A3" interface) of

the system

power supply network: network interconnecting the power source and the ICT equipment

reference test voltage: voltage used as a reference to define the test voltage in the present document

NOTE: The test voltage may be also a percentage of this voltage.

system block: functional group of ICT equipment depending for its operation and performance on its connection to the

same power supply

telecommunication centre: any location where ICT equipment is installed and is the sole responsibility of the operator

3.2 Symbols
For the purposes of the present document, the following symbols apply:
Ω ohm
k Ω Kilo ohm
°C Celsius
ETSI
---------------------- Page: 11 ----------------------
SIST EN 300 132-3 V2.2.1:2021
10 ETSI EN 300 132-3 V2.2.1 (2021-07)
A Ampere
di/dt derivative of a considered current versus time
Hz Hertz
I current
I maximum steady state current drain at 260 VDC at interface "A3"

I maximum steady state current drain in the abnormal service voltage range at interface "A3"

mss
I current rating of the over-current protective device
I peak inrush current at interface "A3"
I maximum steady state current drain at U at interface "A3"
UT T
m meter
ms milli seconds
s seconds
T time duration of the inrush current pulse at 50 % of Ip
U output voltage range of a generator
U Reference Test Voltage
V Volt
W Watt
µs micro seconds
3.3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
AC Alternating Current
CB Circuit Breaker
CLD Current Limiting Device
DC Direct Current
DC/DC DC converter
EE Environmental Engeneering
EMC ElectroMagnetic Compatibility
EN European Standard
ERM Electromagnetic compatibility and Radio spectrum Matters
EUT Equipment Under Test
ICT Information and Communication Technology
N Neutral conductor
PE Protective Earth
VAC Volts Alternating Current
VDC Volts Direct Current
VRLA Valve Regulated Lead Acid
4 Power interface "A3"

The power supply interface "A3" in figure 1, is a physical point to which all the requirements are related. This point is

situated at the power input terminals of the ICT equipment.

Examples of configurations in which interface "A3" is identified are given in annex B.

Basic rules for marking of conductors and connectors shall be in accordance with EN 60445 [9].

ETSI
---------------------- Page: 12 ----------------------
SIST EN 300 132-3 V2.2.1:2021
11 ETSI EN 300 132-3 V2.2.1 (2021-07)
(+)
telecom/datacom (ICT)
(-)
Power suppl y
equipment
system block
(+) Positive DC terminal.
(-) Negative DC terminal.
PE Protective Earth.
Figure 1: General identification of the interface "A3"
5 DC interface requirements
5.0 General

The definition of the DC interface voltages ranges and typical operating voltage values are illustrated in annex G.

5.1 Nominal voltage

The selected battery in general determines this nominal voltage, the operating voltage and the normal service voltage

range in the system.

NOTE 1: For example, 336 V is a nominal voltage defined with 168 lead-acid battery cells multiplied by the

nominal cell voltage 2 V. This nominal DC voltage is equivalent to 48 V multiplied by 7. It allows the use

of existing 48 V battery rack (e.g. Lithium battery racks). There may be other nominal voltage defined

with different number of cells e.g. 156 lead-acid battery cells that lead to 312 V nominal voltage. Other

battery technologies are possible in the future and will influence nominal voltage as well. For detailed

calculation, refer to the annex C.

NOTE 2: In an architecture with a boost converter down-stream the battery, the operating voltage is linked to the

Nominal Voltage determined in clause 5.1 provided that converter output voltage is within the Normal

Service Voltage range.
5.2 Normal service voltage range at interface "A3"

The normal service voltage range at powering interface "A3" of ICT equipment shall be as follows:

• minimum voltage: 260 VDC;
• maximum voltage: 400 VDC.

NOTE 1: The voltage at the output of the power supply takes into account the voltage drop in the cable at

maximum steady current I and/or the maximum battery charge to stay in the normal service voltage

range at the interface "A3" as explained in annexes A, B, C and G.

NOTE 2: For examples on how to calculate normal service voltage range, refer to annex C.

ETSI
---------------------- Page: 13 ----------------------
SIST EN 300 132-3 V2.2.1:2021
12 ETSI EN 300 132-3 V2.2.1 (2021-07)
5.3 Normal operating voltage range at interface "A3"

The normal operating voltage range at interface "A3" is defined by the voltage levels where the system will operate

most of the time under normal operating conditions; this range shall be within the normal service voltage range.

The normal operating voltage is a typical voltage inside the normal operating voltage range.

NOTE 1: Examples of normal operating voltages are 354 V and 380 V.

354 V corresponds to 156 VRLA cells in floating mode (351 V to 359 V with 2,25 V to 2,30 V per cell)

and with no voltage drop in the power distribution.

380 V corresponds to 168 VRLA cells in floating mode (378 V to 386 V with 2,25 V to 2,30 V per cell)

and with no voltage drop in the power distribution.

NOTE 2: For examples on how to calculate normal operating voltage range, refer to annex C.

5.4 Reference test voltage (U ) at interface "A3"
The reference test voltage (U ) for ICT equipment is defined at:
U = 365 V ± 15 V

NOTE: The powering solution should work in any site even with very long power cables i.e. U at the input of

ICT equipment is lower than power supply output. For constant power ICT equipment, the current is

increasing as a function of decreasing voltage.
5.5 Abnormal service voltage ranges at interface "A3"

The ICT equipment may be subjected to steady state voltage out of the normal service voltage range. Limits of

abnormal service voltage range are defined as follows:
• 0 V < U < 260 V
...

ETSI EN 300 132-3 V2.2.1 (2021-07)
EUROPEAN STANDARD
Environmental Engineering (EE);
Power supply interface at the input of Information and
Communication Technology (ICT) equipment;
Part 3: Up to 400 V Direct Current (DC)
---------------------- Page: 1 ----------------------
2 ETSI EN 300 132-3 V2.2.1 (2021-07)
Reference
REN/EE-0265
Keywords
environment, interface, power supply
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE
Tel.: +33 4 92 94 42 00 Fax: +33 4 93 65 47 16
Siret N° 348 623 562 00017 - APE 7112B
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° w061004871
Important notice
The present document can be downloaded from:
http://www.etsi.org/standards-search

The present document may be made available in electronic versions and/or in print. The content of any electronic and/or

print versions of the present document shall not be modified without the prior written authorization of ETSI. In case of any

existing or perceived difference in contents between such versions and/or in print, the prevailing version of an ETSI

deliverable is the one made publicly available in PDF format at www.etsi.org/deliver.

Users of the present document should be aware that the document may be subject to revision or change of status.

Information on the current status of this and other ETSI documents is available at

https://portal.etsi.org/TB/ETSIDeliverableStatus.aspx

If you find errors in the present document, please send your comment to one of the following services:

https://portal.etsi.org/People/CommiteeSupportStaff.aspx
Notice of disclaimer & limitation of liability

The information provided in the present deliverable is directed solely to professionals who have the appropriate degree of

experience to understand and interpret its content in accordance with generally accepted engineering or

other professional standard and applicable regulations.

No recommendation as to products and services or vendors is made or should be implied.

In no event shall ETSI be held liable for loss of profits or any other incidental or consequential damages.

Any software contained in this deliverable is provided "AS IS" with no warranties, express or implied, including but not

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The content of the PDF version shall not be modified without the written authorization of ETSI.

The copyright and the foregoing restriction extend to reproduction in all media.
© ETSI 2021.
All rights reserved.
ETSI
---------------------- Page: 2 ----------------------
3 ETSI EN 300 132-3 V2.2.1 (2021-07)
Contents

Intellectual Property Rights ................................................................................................................................ 5

Foreword ............................................................................................................................................................. 5

Modal verbs terminology .................................................................................................................................... 6

1 Scope ........................................................................................................................................................ 7

2 References ................................................................................................................................................ 7

2.1 Normative references ......................................................................................................................................... 7

2.2 Informative references ........................................................................................................................................ 8

3 Definition of terms, symbols and abbreviations ....................................................................................... 8

3.1 Terms .................................................................................................................................................................. 8

3.2 Symbols .............................................................................................................................................................. 9

3.3 Abbreviations ................................................................................................................................................... 10

4 Power interface "A3" .............................................................................................................................. 10

5 DC interface requirements ...................................................................................................................... 11

5.0 General ............................................................................................................................................................. 11

5.1 Nominal voltage ............................................................................................................................................... 11

5.2 Normal service voltage range at interface "A3" ............................................................................................... 11

5.3 Normal operating voltage range at interface "A3" ........................................................................................... 12

5.4 Reference test voltage (U ) at interface "A3" ................................................................................................... 12

5.5 Abnormal service voltage ranges at interface "A3" .......................................................................................... 12

6 Abnormal conditions: Voltage variations, voltage dips, short interruptions and voltage surges at

interface "A3" ......................................................................................................................................... 13

6.0 General ............................................................................................................................................................. 13

6.1 Voltage variations............................................................................................................................................. 13

6.2 Voltage dips...................................................................................................................................................... 14

6.3 Short interruptions ............................................................................................................................................ 14

6.4 Voltage surges .................................................................................................................................................. 15

7 DC Supply protection ............................................................................................................................. 16

8 Maximum steady state current I , in the normal service voltage range ................................................. 16

9 Inrush current on connection to interface "A3" ...................................................................................... 17

9.1 Limits ............................................................................................................................................................... 17

9.2 Measurements ................................................................................................................................................... 18

10 Installation and Cabling, Earthing and Bonding .................................................................................... 19

11 Electrical Safety requirements ................................................................................................................ 19

12 EMC requirements at the input of ICT equipment ................................................................................. 20

Annex A (informative): Power supply considerations ......................................................................... 21

Annex B (informative): Identification of interface "A3" .................................................................... 22

Annex C (informative): Calculation of the extreme DC voltage range at interface "A3" ............... 23

Annex D (informative): Guide for defining inrush current energy, measuring inrush current

and test generator peak inrush current drive capability............................ 24

D.0 General ................................................................................................................................................... 24

D.1 Measurement .......................................................................................................................................... 24

D.2 Test generator peak inrush current drive capability ............................................................................... 25

D.3 Example of inrush current waveform ..................................................................................................... 25

ETSI
---------------------- Page: 3 ----------------------
4 ETSI EN 300 132-3 V2.2.1 (2021-07)

Annex E (informative): Dimensioning of over-current protective devices ........................................ 27

Annex F (informative): Details of the voltage transient measurement in the most common

case of distribution and protective devices .................................................. 28

Annex G (informative): Diagram of voltage ranges and values at the interface "A3" .................... 30

History .............................................................................................................................................................. 31

ETSI
---------------------- Page: 4 ----------------------
5 ETSI EN 300 132-3 V2.2.1 (2021-07)
Intellectual Property Rights
Essential patents

IPRs essential or potentially essential to normative deliverables may have been declared to ETSI. The declarations

pertaining to these essential IPRs, if any, are publicly available for ETSI members and non-members, and can be

found in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to

ETSI in respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the

ETSI Web server (https://ipr.etsi.org/).

Pursuant to the ETSI Directives including the ETSI IPR Policy, no investigation regarding the essentiality of IPRs,

including IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not

referenced in ETSI SR 000 314 (or the updates on the ETSI Web server) which are, or may be, or may become,

essential to the present document.
Trademarks

The present document may include trademarks and/or tradenames which are asserted and/or registered by their owners.

ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no

right to use or reproduce any trademark and/or tradename. Mention of those trademarks in the present document does

not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks.

DECT™, PLUGTESTS™, UMTS™ and the ETSI logo are trademarks of ETSI registered for the benefit of its

Members. 3GPP™ and LTE™ are trademarks of ETSI registered for the benefit of its Members and of the 3GPP

Organizational Partners. oneM2M™ logo is a trademark of ETSI registered for the benefit of its Members and of the

oneM2M Partners. GSM and the GSM logo are trademarks registered and owned by the GSM Association.

Foreword

This European Standard (EN) has been produced by ETSI Technical Committee Environmental Engineering (EE).

The present document concerns the requirements for the interface between Information and Communication

Technology (ICT) equipment and its power supply. It includes requirements relating to its stability and measurement.

Various other references and detailed measurement and test arrangements are contained in informative annexes.

The introduced interface up to 400 V Direct Current (DC) is considering power consumption increase and equipment

power density increase in order to get higher energy efficiency with less material than with low voltage -48 VDC or

permanent AC powering solution.

The up to 400 VDC interface could also simplify the use of renewable energy source with DC output such as

photovoltaic generator.

The present document is part 3 of a multi-part deliverable covering Environmental Engineering (EE); Power supply

interface at the input to Information and Communication Technology ICT equipment, as identified below:

Part 1: "Alternating Current (AC)";
Part 2: "-48 V Direct Current (DC)";
Part 3: "Up to 400 V Direct Current (DC)";
Part 4: "Up to 400 V Direct Current (DC) and Alternating Current (AC)".
ETSI
---------------------- Page: 5 ----------------------
6 ETSI EN 300 132-3 V2.2.1 (2021-07)
National transposition dates
Date of adoption of this EN: 30 June 2021
Date of latest announcement of this EN (doa): 30 September 2021
Date of latest publication of new National Standard
or endorsement of this EN (dop/e): 31 March 2022
Date of withdrawal of any conflicting National Standard (dow): 31 March 2022
Modal verbs terminology

In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and

"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of

provisions).

"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.

ETSI
---------------------- Page: 6 ----------------------
7 ETSI EN 300 132-3 V2.2.1 (2021-07)
1 Scope

The present document contains requirements and measurements methods for the physical interface "A3" that is situated

between the power supply system(s) and the power consuming ICT equipment:

• the nominal voltage at power interface "A3" of ICT equipment defined in the present document is DC voltage up

to 400 V;

• the output performance of the power equipment including the cable network at the interface "A3";

• the input of the ICT equipment connected to interface "A3".

The DC power can be supplied by a DC output power system e.g. via on-grid AC rectifiers, from DC/DC converters in

solar systems, fuel cells, standby generators including a battery backup.

The present document aims at providing compatibility at interface "A3" between the power supply equipment and different

ICT equipment (including/monitoring, cooling system, etc.) connected to the same power supply.

The requirements are defined for the purpose of the present document:

• to identify a power supply system with the same characteristics for all ICT equipment defined in the area of

application; the area of application may be any location where the interface "A3" is used i.e.

telecommunication centres, Radio Base Stations, datacentres and customer premises;

• to facilitate interworking of different loads;
• to facilitate the standardization of power supply systems for ICT equipment;

• to facilitate the installation, operation and maintenance in the same network of ICT equipment and systems

from different origins;

• to secure robustness against temporary voltage deviations and transients during abnormal conditions.

General requirements for safety and EMC are out of the scope of the present document series unless specific

requirement not defined in existing safety or EMC standards.
2 References
2.1 Normative references

References are either specific (identified by date of publication and/or edition number or version number) or

non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the

referenced document (including any amendments) applies.

Referenced documents which are not found to be publicly available in the expected location might be found at

https://docbox.etsi.org/Reference.

NOTE: While any hyperlinks included in the present clause were valid at the time of publication, ETSI cannot

guarantee their long term validity.

The following referenced documents are necessary for the application of the present document.

[1] IEC 60947-2: "Low-voltage switchgear and controlgear - Part 2: Circuit-breakers".

[2] IEC 60269-1: "Low-voltage fuses - Part 1: General requirements".

[3] IEC 61000-4-5: "Electromagnetic compatibility (EMC) - Part 4-5: Testing and measurement

techniques - Surge immunity test".
ETSI
---------------------- Page: 7 ----------------------
8 ETSI EN 300 132-3 V2.2.1 (2021-07)

[4] IEC 61000-4-29: "Electromagnetic compatibility (EMC) - Part 4-29: Testing and measurement

techniques - Voltage dips, short interruptions and voltage variations on d.c. input power port

immunity tests".

[5] IEC 60898-2: "Electrical accessories - Circuit-breakers for overcurrent protection for household

and similar installations - Part 2: Circuit-breakers for AC and DC operation".

[6] ETSI EN 301 605 (V1.1.1) (2013): "Environmental Engineering (EE); Earthing and bonding of

400 VDC data and telecom (ICT) equipment".

[7] Recommendation ITU-T L.1207 (2018): "Progressive migration of telecommunication/information

and communication technology site to 400 VDC sources and distribution".

[8] IEC 60364-4-41: "Low voltage electrical installations - Part 4-41: Protection for safety - Protection

against electric shock".

[9] EN 60445: "Basic and safety principle for man-machine interface, marking and identification-

Identification of equipment terminals, conductor terminations and conductors". (Produced by

CENELEC).

[10] Recommendation ITU-T L.1203 (2016): "Colour and marking identification of up to 400 VDC

power distribution for information and communication technology systems".
2.2 Informative references

References are either specific (identified by date of publication and/or edition number or version number) or

non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the

referenced document (including any amendments) applies.

NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee

their long term validity.

The following referenced documents are not necessary for the application of the present document but they assist the

user with regard to a particular subject area.

[i.1] ETSI EN 300 132-2: "Environmental Engineering (EE); Power supply interface at the input of

Information and Communication Technology (ICT) equipment; Part 2: -48 V Direct Current

(DC)".

[i.2] IEC 60050-601: "International Electrotechnical Vocabulary. Chapter 601: Generation,

transmission and distribution of electricity - General".

[i.3] ETSI EN 300 386: "Electromagnetic compatibility and Radio spectrum Matters (ERM);

Telecommunication network equipment; ElectroMagnetic Compatibility (EMC) requirements".

[i.4] EN 62368-1: "Audio/video, information and communication technology equipment - Part 1: Safety

requirements". (Produced by CENELEC).
3 Definition of terms, symbols and abbreviations
3.1 Terms
For the purposes of the present document, the following terms apply:

abnormal service voltage ranges: steady-state voltage ranges over which the ICT equipment will not be expected to

maintain normal service but will survive undamaged
area of application: any location where the interface "A3" is used

NOTE: I.e. telecommunication centres, Radio Base Stations, datacentres and customer premises.

ETSI
---------------------- Page: 8 ----------------------
9 ETSI EN 300 132-3 V2.2.1 (2021-07)
customer premises: any location which is the sole responsibility of the customer

dual feeding system: independent power systems i.e. two separate power sources (A+B)

high-ohmic distribution system: distribution system in which the equipment is connected separately to the battery

with added impedance

NOTE 1: The high impedance can be achieved with long cables and in some cases additional resistors are installed.

NOTE 2: With this distribution the undervoltage effects of fuse blowing transients are reduced on other equipment

connected to the battery.
ICT equipment: telecommunication or datacommunication equipment

independent power distribution: redundant power distribution i.e. dual feeders (A+B) from two separate power

sources (A+B) or a single power source

NOTE: Equipment having two power feeds is fitted with OR-ing devices or separate power supply units.

interface "A3": power interface at the input terminals of ICT, physical point, at which power supply is connected in

order to operate the ICT equipment
load unit: power consuming equipment, that is part of a system block

nominal voltage: value of the voltage by which the electrical installation or part of the electrical installation is

designated and identified

NOTE: This definition is based on nominal voltage defined in IEC 60050-601 [i.2].

normal operating condition: typical environmental and powering conditions for operation of ICT equipment, power

supply, power distribution and battery

normal operating voltage: typical value of the voltage at "A3" interface within the normal operating voltage range

normal operating voltage range: voltage range at "A3" interface where the system operates most of the time, e.g. in

general linked to battery floating voltage

normal service: service mode where ICT equipment operates within its specification

normal service voltage range: range of the steady-state voltage at the "A3" interface over which the equipment will

maintain normal service

NOTE: In general this wider than the normal operating voltage range as it includes a part of the battery discharge

voltage range.

operating voltage: value of the voltage under normal conditions, at a given instant and a given point ("A3" interface) of

the system

power supply network: network interconnecting the power source and the ICT equipment

reference test voltage: voltage used as a reference to define the test voltage in the present document

NOTE: The test voltage may be also a percentage of this voltage.

system block: functional group of ICT equipment depending for its operation and performance on its connection to the

same power supply

telecommunication centre: any location where ICT equipment is installed and is the sole responsibility of the operator

3.2 Symbols
For the purposes of the present document, the following symbols apply:
Ω ohm
k Ω Kilo ohm
°C Celsius
ETSI
---------------------- Page: 9 ----------------------
10 ETSI EN 300 132-3 V2.2.1 (2021-07)
A Ampere
di/dt derivative of a considered current versus time
Hz Hertz
I current
I maximum steady state current drain at 260 VDC at interface "A3"

I maximum steady state current drain in the abnormal service voltage range at interface "A3"

mss
I current rating of the over-current protective device
I peak inrush current at interface "A3"
I maximum steady state current drain at U at interface "A3"
UT T
m meter
ms milli seconds
s seconds
T time duration of the inrush current pulse at 50 % of Ip
U output voltage range of a generator
U Reference Test Voltage
V Volt
W Watt
µs micro seconds
3.3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
AC Alternating Current
CB Circuit Breaker
CLD Current Limiting Device
DC Direct Current
DC/DC DC converter
EE Environmental Engeneering
EMC ElectroMagnetic Compatibility
EN European Standard
ERM Electromagnetic compatibility and Radio spectrum Matters
EUT Equipment Under Test
ICT Information and Communication Technology
N Neutral conductor
PE Protective Earth
VAC Volts Alternating Current
VDC Volts Direct Current
VRLA Valve Regulated Lead Acid
4 Power interface "A3"

The power supply interface "A3" in figure 1, is a physical point to which all the requirements are related. This point is

situated at the power input terminals of the ICT equipment.

Examples of configurations in which interface "A3" is identified are given in annex B.

Basic rules for marking of conductors and connectors shall be in accordance with EN 60445 [9].

ETSI
---------------------- Page: 10 ----------------------
11 ETSI EN 300 132-3 V2.2.1 (2021-07)
(+)
telecom/datacom (ICT)
(-)
Power suppl y
equipment
system block
(+) Positive DC terminal.
(-) Negative DC terminal.
PE Protective Earth.
Figure 1: General identification of the interface "A3"
5 DC interface requirements
5.0 General

The definition of the DC interface voltages ranges and typical operating voltage values are illustrated in annex G.

5.1 Nominal voltage

The selected battery in general determines this nominal voltage, the operating voltage and the normal service voltage

range in the system.

NOTE 1: For example, 336 V is a nominal voltage defined with 168 lead-acid battery cells multiplied by the

nominal cell voltage 2 V. This nominal DC voltage is equivalent to 48 V multiplied by 7. It allows the use

of existing 48 V battery rack (e.g. Lithium battery racks). There may be other nominal voltage defined

with different number of cells e.g. 156 lead-acid battery cells that lead to 312 V nominal voltage. Other

battery technologies are possible in the future and will influence nominal voltage as well. For detailed

calculation, refer to the annex C.

NOTE 2: In an architecture with a boost converter down-stream the battery, the operating voltage is linked to the

Nominal Voltage determined in clause 5.1 provided that converter output voltage is within the Normal

Service Voltage range.
5.2 Normal service voltage range at interface "A3"

The normal service voltage range at powering interface "A3" of ICT equipment shall be as follows:

• minimum voltage: 260 VDC;
• maximum voltage: 400 VDC.

NOTE 1: The voltage at the output of the power supply takes into account the voltage drop in the cable at

maximum steady current I and/or the maximum battery charge to stay in the normal service voltage

range at the interface "A3" as explained in annexes A, B, C and G.

NOTE 2: For examples on how to calculate normal service voltage range, refer to annex C.

ETSI
---------------------- Page: 11 ----------------------
12 ETSI EN 300 132-3 V2.2.1 (2021-07)
5.3 Normal operating voltage range at interface "A3"

The normal operating voltage range at interface "A3" is defined by the voltage levels where the system will operate

most of the time under normal operating conditions; this range shall be within the normal service voltage range.

The normal operating voltage is a typical voltage inside the normal operating voltage range.

NOTE 1: Examples of normal operating voltages are 354 V and 380 V.

354 V corresponds to 156 VRLA cells in floating mode (351 V to 359 V with 2,25 V to 2,30 V per cell)

and with no voltage drop in the power distribution.

380 V corresponds to 168 VRLA cells in floating mode (378 V to 386 V with 2,25 V to 2,30 V per cell)

and with no voltage drop in the power distribution.

NOTE 2: For examples on how to calculate normal operating voltage range, refer to annex C.

5.4 Reference test voltage (U ) at interface "A3"
The reference test voltage (U ) for ICT equipment is defined at:
U = 365 V ± 15 V

NOTE: The powering solution should work in any site even with very long power cables i.e. U at the input of

ICT equipment is lower than power supply output. For constant power ICT equipment, the current is

increasing as a function of decreasing voltage.
5.5 Abnormal service voltage ranges at interface "A3"

The ICT equipment may be subjected to steady state voltage out of the normal service voltage range. Limits of

abnormal service voltage range are defined as follows:
• 0 V < U < 260 V
• 400 V < U < 410 V for 1 s
• 410 < U < 420 V for maximum 10 ms

For example, it may be generated from undervoltage or overvoltage at battery end of discharge cycle or battery end of

charge or rectifier regulation/control failures.

ICT equipment with interface "A3" shall not suffer any damage when subjected to the abnormal voltage range.

After the restoration of the supply from the abnormal service voltage range to the normal service voltage range, the ICT

equipment shall fulfil the following performance criteria:
• the ICT equipment shall not suffer any damage;

• the ICT equipment shall be able to automatically resume operation according to its specifications when the

voltage comes back into the normal service voltage range.

NOTE: The second criterion implies that abnormal service voltage should not lead to the disconnection of power

supply units e.g. by causing circuit breakers, fuses or other such devices to operate.

ETSI
---------------------- Page: 12 ----------------------
13 ETSI EN 300 132-3 V2.2.1 (2021-07)
6 Abnormal conditions: Voltage variations, voltage
dips, short interruptions and voltage surges at
interface "A3"
6.0 General

Under abnormal conditions, voltage values outside the normal service voltage range may occur for short time.

The de
...

Draft ETSI EN 300 132-3 V2.1.13 (2021-04)
EUROPEAN STANDARD
Environmental Engineering (EE);
Power supply interface at the input of Information and
Communication Technology (ICT) equipment;
Part 3: Up to 400 V Direct Current (DC)
---------------------- Page: 1 ----------------------
2 Draft ETSI EN 300 132-3 V2.1.13 (2021-04)
Reference
REN/EE-0265
Keywords
environment, interface, power supply
ETSI
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Copyright Notification

No part may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying

and microfilm except as authorized by written permission of ETSI.

The content of the PDF version shall not be modified without the written authorization of ETSI.

The copyright and the foregoing restriction extend to reproduction in all media.
© ETSI 2021.
All rights reserved.

DECT™, PLUGTESTS™, UMTS™ and the ETSI logo are trademarks of ETSI registered for the benefit of its Members.

3GPP™ and LTE™ are trademarks of ETSI registered for the benefit of its Members and

of the 3GPP Organizational Partners.

oneM2M™ logo is a trademark of ETSI registered for the benefit of its Members and

of the oneM2M Partners.
GSM and the GSM logo are trademarks registered and owned by the GSM Association.
ETSI
---------------------- Page: 2 ----------------------
3 Draft ETSI EN 300 132-3 V2.1.13 (2021-04)
Contents

Intellectual Property Rights ................................................................................................................................ 5

Foreword ............................................................................................................................................................. 5

Modal verbs terminology .................................................................................................................................... 6

1 Scope ........................................................................................................................................................ 7

2 References ................................................................................................................................................ 7

2.1 Normative references ......................................................................................................................................... 7

2.2 Informative references ........................................................................................................................................ 8

3 Definition of terms, symbols and abbreviations ....................................................................................... 8

3.1 Terms .................................................................................................................................................................. 8

3.2 Symbols .............................................................................................................................................................. 9

3.3 Abbreviations ................................................................................................................................................... 10

4 Power interface "A3" .............................................................................................................................. 10

5 DC interface requirements ...................................................................................................................... 11

5.0 General ............................................................................................................................................................. 11

5.1 Nominal voltage ............................................................................................................................................... 11

5.2 Normal service voltage range at interface "A3" ............................................................................................... 11

5.3 Normal operating voltage range at interface "A3" ........................................................................................... 12

5.4 Reference test voltage (U ) at interface "A3" ................................................................................................... 12

5.5 Abnormal service voltage ranges at interface "A3" .......................................................................................... 12

6 Abnormal conditions: Voltage variations, voltage dips, short interruptions and voltage surges at

interface "A3" ......................................................................................................................................... 13

6.0 General ............................................................................................................................................................. 13

6.1 Voltage variations............................................................................................................................................. 13

6.2 Voltage dips...................................................................................................................................................... 14

6.3 Short interruptions ............................................................................................................................................ 14

6.4 Voltage surges .................................................................................................................................................. 15

7 DC Supply protection ............................................................................................................................. 16

8 Maximum steady state current I , in the normal service voltage range ................................................. 16

9 Inrush current on connection to interface "A3" ...................................................................................... 17

9.1 Limits ............................................................................................................................................................... 17

9.2 Measurements ................................................................................................................................................... 18

10 Installation and Cabling, Earthing and Bonding .................................................................................... 19

11 Electrical Safety requirements ................................................................................................................ 19

12 EMC requirements at the input of ICT equipment ................................................................................. 20

Annex A (informative): Power supply considerations ......................................................................... 21

Annex B (informative): Identification of interface "A3" .................................................................... 22

Annex C (informative): Calculation of the extreme DC voltage range at interface "A3" ............... 23

Annex D (informative): Guide for defining inrush current energy, measuring inrush current

and test generator peak inrush current drive capability............................ 24

D.0 General ................................................................................................................................................... 24

D.1 Measurement .......................................................................................................................................... 24

D.2 Test generator peak inrush current drive capability ............................................................................... 25

ETSI
---------------------- Page: 3 ----------------------
4 Draft ETSI EN 300 132-3 V2.1.13 (2021-04)

D.3 Example of inrush current waveform ..................................................................................................... 25

Annex E (informative): Dimensioning of over-current protective devices ........................................ 27

Annex F (informative): Details of the voltage transient measurement in the most common

case of distribution and protective devices .................................................. 28

Annex G (informative): Diagram of voltage ranges and values at the interface "A3" .................... 30

History .............................................................................................................................................................. 31

ETSI
---------------------- Page: 4 ----------------------
5 Draft ETSI EN 300 132-3 V2.1.13 (2021-04)
Intellectual Property Rights
Essential patents

IPRs essential or potentially essential to normative deliverables may have been declared to ETSI. The information

pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found

in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in

respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web

server (https://ipr.etsi.org/).

Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee

can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web

server) which are, or may be, or may become, essential to the present document.
Trademarks

The present document may include trademarks and/or tradenames which are asserted and/or registered by their owners.

ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no

right to use or reproduce any trademark and/or tradename. Mention of those trademarks in the present document does

not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks.

Foreword

This draft European Standard (EN) has been produced by ETSI Technical Committee Environmental Engineering (EE),

and is now submitted for the combined Public Enquiry and Vote phase of the ETSI standards EN Approval Procedure.

The present document concerns the requirements for the interface between Information and Communication

Technology (ICT) equipment and its power supply. It includes requirements relating to its stability and measurement.

Various other references and detailed measurement and test arrangements are contained in informative annexes.

The introduced interface up to 400 V Direct Current (DC) is considering power consumption increase and equipment

power density increase in order to get higher energy efficiency with less material than with low voltage -48 VDC or

permanent AC powering solution.

The up to 400 VDC interface could also simplify the use of renewable energy source with DC output such as

photovoltaic generator.

The present document is part 3 of a multi-part deliverable covering Environmental Engineering (EE); Power supply

interface at the input to Information and Communication Technology ICT equipment, as identified below:

Part 1: "Alternating Current (AC)";
Part 2: "-48 V Direct Current (DC)";
Part 3: "Up to 400 V Direct Current (DC)";
Part 4: "Up to 400 V Direct Current (DC) and Alternating Current (AC)".
Proposed national transposition dates
Date of latest announcement of this EN (doa): 3 months after ETSI publication
Date of latest publication of new National Standard
or endorsement of this EN (dop/e): 6 months after doa

Date of withdrawal of any conflicting National Standard (dow): 6 months after doa

ETSI
---------------------- Page: 5 ----------------------
6 Draft ETSI EN 300 132-3 V2.1.13 (2021-04)
Modal verbs terminology

In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and

"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of

provisions).

"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.

ETSI
---------------------- Page: 6 ----------------------
7 Draft ETSI EN 300 132-3 V2.1.13 (2021-04)
1 Scope

The present document contains requirements and measurements methods for the physical interface "A3" that is situated

between the power supply system(s) and the power consuming ICT equipment:

• the nominal voltage at power interface "A3" of ICT equipment defined in the present document is DC voltage up

to 400 V;

• the output performance of the power equipment including the cable network at the interface "A3";

• the input of the ICT equipment connected to interface "A3".

The DC power can be supplied by a DC output power system e.g. via on-grid AC rectifiers, from DC/DC converters in

solar systems, fuel cells, standby generators including a battery backup.

The present document aims at providing compatibility at interface "A3" between the power supply equipment and different

ICT equipment (including/monitoring, cooling system, etc.) connected to the same power supply.

The requirements are defined for the purpose of the present document:

• to identify a power supply system with the same characteristics for all ICT equipment defined in the area of

application; the area of application may be any location where the interface "A3" is used i.e.

telecommunication centres, Radio Base Stations, datacentres and customer premises;

• to facilitate interworking of different loads;
• to facilitate the standardization of power supply systems for ICT equipment;

• to facilitate the installation, operation and maintenance in the same network of ICT equipment and systems

from different origins.

• to secure robustness against temporary voltage deviations and transients during abnormal conditions

General requirements for safety and EMC are out of the scope of the present document series unless specific

requirement not defined in existing safety or EMC standards.
2 References
2.1 Normative references

References are either specific (identified by date of publication and/or edition number or version number) or

non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the

referenced document (including any amendments) applies.

Referenced documents which are not found to be publicly available in the expected location might be found at

https://docbox.etsi.org/Reference.

NOTE: While any hyperlinks included in the present clause were valid at the time of publication, ETSI cannot

guarantee their long term validity.

The following referenced documents are necessary for the application of the present document.

[1] IEC 60947-2: "Low-voltage switchgear and controlgear - Part 2: Circuit-breakers".

[2] IEC 60269-1: "Low-voltage fuses - Part 1: General requirements".

[3] IEC 61000-4-5: "Electromagnetic compatibility (EMC) - Part 4-5: Testing and measurement

techniques - Surge immunity test".
ETSI
---------------------- Page: 7 ----------------------
8 Draft ETSI EN 300 132-3 V2.1.13 (2021-04)

[4] IEC 61000-4-29: "Electromagnetic compatibility (EMC) - Part 4-29: Testing and measurement

techniques - Voltage dips, short interruptions and voltage variations on d.c. input power port

immunity tests".

[5] IEC 60898-2: "Electrical accessories - Circuit-breakers for overcurrent protection for household

and similar installations - Part 2: Circuit-breakers for AC and DC operation".

[6] ETSI EN 301 605 (V1.1.1) (2013): "Environmental Engineering (EE); Earthing and bonding of

400 VDC data and telecom (ICT) equipment".

[7] Recommendation ITU-T L.1207 (2018): "Progressive migration of telecommunication/information

and communication technology site to 400 VDC sources and distribution".

[8] IEC 60364-4-41: "Low voltage electrical installations - Part 4-41: Protection for safety - Protection

against electric shock".

[9] EN 60445: "Basic and safety principle for man-machine interface, marking and identification-

Identification of equipment terminals, conductor terminations and conductors". (Produced by

CENELEC).

[10] Recommendation ITU-T L.1203 (2016): "Colour and marking identification of up to 400 VDC

power distribution for information and communication technology systems".
2.2 Informative references

References are either specific (identified by date of publication and/or edition number or version number) or

non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the

referenced document (including any amendments) applies.

NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee

their long term validity.

The following referenced documents are not necessary for the application of the present document but they assist the

user with regard to a particular subject area.

[i.1] ETSI EN 300 132-2: "Environmental Engineering (EE); Power supply interface at the input of

Information and Communication Technology (ICT) equipment; Part 2: -48 V Direct Current

(DC)".

[i.2] IEC 60050-601: "International Electrotechnical Vocabulary. Chapter 601: Generation,

transmission and distribution of electricity - General".

[i.3] ETSI EN 300 386: "Electromagnetic compatibility and Radio spectrum Matters (ERM);

Telecommunication network equipment; ElectroMagnetic Compatibility (EMC) requirements".

[i.4] EN 62368-1: "Audio/video, information and communication technology equipment - Part 1: Safety

requirements". (Produced by CENELEC).
3 Definition of terms, symbols and abbreviations
3.1 Terms
For the purposes of the present document, the following terms apply:

abnormal service voltage ranges: steady-state voltage ranges over which the ICT equipment will not be expected to

maintain normal service but will survive undamaged
area of application: any location where the interface "A3" is used

NOTE: i.e. telecommunication centres, Radio Base Stations, datacentres and customer premises

ETSI
---------------------- Page: 8 ----------------------
9 Draft ETSI EN 300 132-3 V2.1.13 (2021-04)
customer premises: any location which is the sole responsibility of the customer

dual feeding system: independent power systems i.e. two separate power sources (A+B)

high-Ohmic distribution system: distribution system in which the equipment is connected separately to the battery

with added impedance

NOTE 1: The high impedance can be achieved with long cables and in some cases additional resistors are installed.

NOTE 2: With this distribution the undervoltage effects of fuse blowing transients are reduced on other equipment

connected to the battery.
ICT equipment: telecommunication or datacommunication equipment

independent power distribution: redundant power distribution i.e. dual feeders (A+B) from two separate power

sources (A+B) or a single power source

NOTE: Equipment having two power feeds is fitted with OR-ing devices or separate power supply units.

interface "A3": power interface at the input terminals of ICT, physical point, at which power supply is connected in

order to operate the ICT equipment
load unit: power consuming equipment, that is part of a system block

nominal voltage: value of the voltage by which the electrical installation or part of the electrical installation is

designated and identified.

NOTE: This definition is based on nominal voltage defined in IEC 60050-601 [i.2].

normal operating condition: typical environmental and powering conditions for operation of ICT equipment, power

supply, power distribution and battery

normal operating voltage: typical value of the voltage at "A3" interface within the normal operating voltage range

normal operating voltage range: voltage range at "A3" interface where the system operates most of the time, e.g. in

general linked to battery floating voltage

normal service: service mode where ICT equipment operates within its specification

normal service voltage range: range of the steady-state voltage at the "A3" interface over which the equipment will

maintain normal service.

NOTE: In general this wider than the normal operating voltage range as it includes a part of the battery discharge

voltage range.

operating voltage: value of the voltage under normal conditions, at a given instant and a given point ("A3" interface) of

the system

power supply network: network interconnecting the power source and the ICT equipment

reference test voltage: voltage used as a reference to define the test voltage in the present document

NOTE: The test voltage may be also a percentage of this voltage.

system block: functional group of ICT equipment depending for its operation and performance on its connection to the

same power supply

telecommunication centre: any location where ICT equipment is installed and is the sole responsibility of the operator

3.2 Symbols
For the purposes of the present document, the following symbols apply:
Ω ohm
k Ω Kilo ohm
°C Celsius
ETSI
---------------------- Page: 9 ----------------------
10 Draft ETSI EN 300 132-3 V2.1.13 (2021-04)
A Ampere
di/dt derivative of a considered current versus time
Hz Hertz
I current
Im maximum steady state current drain at 260 VDC at interface "A3"

I maximum steady state current drain in the abnormal service voltage range at interface "A3"

mss
I current rating of the over-current protective device
I peak inrush current at interface "A3"
maximum steady state current drain at U at interface "A3"
IUT T
m meter
ms milli seconds
s seconds
T time duration of the inrush current pulse at 50 % of Ip
U output voltage range of a generator
Reference Test Voltage
V Volt
W Watt
µs micro seconds
3.3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
AC Alternating Current
CB Circuit Breaker
CLD Current Limiting Device
DC Direct Current
DC/DC DC converter
EE Environmental Engeneering
EMC ElectroMagnetic Compatibility
EN European Standard
ERM Electromagnetic compatibility and Radio spectrum Matters
EUT Equipment Under Test
ICT Information and Communication Technology
N Neutral conductor
PE Protective Earth
VAC Volts Alternating Current
VDC Volts Direct Current
VRLA Valve Regulated Lead Acid
4 Power interface "A3"

The power supply interface "A3" in figure 1, is a physical point to which all the requirements are related. This point is

situated at the power input terminals of the ICT equipment.

Examples of configurations in which interface "A3" is identified are given in annex B.

Basic rules for marking of conductors and connectors shall be in accordance with EN 60445 [9].

ETSI
---------------------- Page: 10 ----------------------
11 Draft ETSI EN 300 132-3 V2.1.13 (2021-04)
(+)
telecom/datacom (ICT)
(-)
Power suppl y
equipment
system block
(+) Positive DC terminal.
(-) Negative DC terminal.
PE Protective Earth.
Figure 1: General identification of the interface "A3"
5 DC interface requirements
5.0 General

The definition of the DC interface voltages ranges and typical operating voltage values are illustrated in annex G.

5.1 Nominal voltage

The selected battery in general determines this nominal voltage, the operating voltage and the normal service voltage

range in the system.

NOTE 1: For example, 336 V is a nominal voltage defined with 168 lead-acid battery cells multiplied by the

nominal cell voltage 2 V. This nominal DC voltage is equivalent to 48 V multiplied by 7. It allows the use

of existing 48 V battery rack (e.g. Lithium battery racks). There may be other nominal voltage defined

with different number of cells e.g. 156 lead-acid battery cells that lead to 312 V nominal voltage. Other

battery technologies are possible in the future and will influence nominal voltage as well. For detailed

calculation, refer to the annex C.

NOTE 2: In an architecture with a boost converter down-stream the battery, the operating voltage is linked to the

Nominal Voltage determined in clause 5.1 provided that converter output voltage is within the Normal

Service Voltage range.
5.2 Normal service voltage range at interface "A3"

The normal service voltage range at powering interface "A3" of ICT equipment shall be as follows:

• minimum voltage: 260 VDC;
• maximum voltage: 400 VDC.

NOTE 1: The voltage at the output of the power supply takes into account the voltage drop in the cable at

maximum steady current Im and/or the maximum battery charge to stay in the normal service voltage

range at the interface "A3" as explained in annexes A, B, C and G.

NOTE 2: For examples on how to calculate normal service voltage range, refer to annex C.

ETSI
---------------------- Page: 11 ----------------------
12 Draft ETSI EN 300 132-3 V2.1.13 (2021-04)
5.3 Normal operating voltage range at interface "A3"

The normal operating voltage range at interface "A3" is defined by the voltage levels where the system will operate

most of the time under normal operating conditions; this range shall be within the normal service voltage range.

The normal operating voltage is a typical voltage inside the normal operating voltage range.

NOTE 1: Examples of normal operating voltages are 354 V and 380 V.

354 V corresponds to 156 VRLA cells in floating mode (351 V to 359 V with 2,25 V to 2,30 V per cell)

and with no voltage drop in the power distribution.

380 V corresponds to 168 VRLA cells in floating mode (378 V to 386 V with 2,25 V to 2,30 V per cell)

and with no voltage drop in the power distribution.

NOTE 2: For examples on how to calculate normal operating voltage range, refer to annex C.

5.4 Reference test voltage (U ) at interface "A3"
The reference test voltage (U ) for ICT equipment is defined at:
U = 365 V ± 15 V

NOTE: The powering solution should work in any site even with very long power cables i.e. U at the input of

ICT equipment is lower than power supply output. For constant power ICT equipment, the current is

increasing as a function of decreasing voltage.
5.5 Abnormal service voltage ranges at interface "A3"

The ICT equipment may be subjected to steady state voltage out of the normal service voltage range. Limits of

abnormal service voltage range are defined as follows:
• 0 V < U < 260 V
• 400 V < U < 410 V for 1 s
• 410 < U < 420 V for maximum 10 ms

For example, it may be generated from undervoltage or overvoltage at battery end of discharge cycle or battery end of

charge or rectifier regulation/control failures.

ICT equipment with interface "A3" shall not suffer any damage when subjected to the abnormal voltage range.

After the restoration of the supply from the abnormal service voltage range to the normal service voltage range, the ICT

equipment shall fulfil the following performance criteria:
• the ICT equipment shall not suffer any damage;

• the ICT equipment shall be able to automatically resume operation according to its specifications when the

voltage comes back into the normal service voltage range.

NOTE: The second criterion implies that abnormal service voltage should not lead to the disconnection of power

supply units e.g. by causing circuit breakers, fuses or other such devices to operate.

ETSI
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13 Draft ETSI EN 300 132-3 V2.1.13 (2021-04)
6 Abnormal conditions: Voltage variations, voltage
dips, short interruptions and voltage surges at
interface "A3"
6.0 General

Under abnormal conditions, voltage values outside the normal service voltage range may occur for short time.

The deviations from the steady-state voltage at the "A3" interface may be caused by:

• Voltage variations.
• Voltage dips.
• Voltage interruptions.
• Voltage surges.

The tests for voltage dips, short interruption and voltage variations shall be conducted in accordance with standard

EN 61000-4-29 [4], chapter 6.1.

The tests for voltage surges shall be conducted in accordance with standard EN 61000-4-5 [3].

Specific criteria to ICT equipment are defined in each test of table 1. The detailed specification of the generator is in

EN 61000-4-29 [4], chapter 6.1. The tests shall be performed on individual modules/subsystems.

6.1 Voltage variations

Test voltages, power supply network and compliance criteria at interface "A3" are defined in table 1.

The test applies to equipment with single and multiple power supply inputs at interface "A3".

Table 1
Test level of Normal Voltage Compliance Criteria on I
...

SLOVENSKI STANDARD
oSIST prEN 300 132-3 V2.1.13:2021
01-junij-2021
Okoljski inženiring (EE) - Napajalni vmesnik na vhodu v informacijsko in
komunikacijsko tehnološko opremo - 3. del: Enosmerni tok (DC) do 400 V

Environmental Engineering (EE) - Power supply interface at the input of Information and

Communication Technology (ICT) equipment - Part 3: Up to 400 V Direct Current (DC)

Ta slovenski standard je istoveten z: ETSI EN 300 132-3 V2.1.13 (2021-04)
ICS:
19.040 Preskušanje v zvezi z Environmental testing
okoljem
35.200 Vmesniška in povezovalna Interface and interconnection
oprema equipment
oSIST prEN 300 132-3 V2.1.13:2021 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
oSIST prEN 300 132-3 V2.1.13:2021
---------------------- Page: 2 ----------------------
oSIST prEN 300 132-3 V2.1.13:2021
Draft ETSI EN 300 132-3 V2.1.13 (2021-04)
EUROPEAN STANDARD
Environmental Engineering (EE);
Power supply interface at the input of Information and
Communication Technology (ICT) equipment;
Part 3: Up to 400 V Direct Current (DC)
---------------------- Page: 3 ----------------------
oSIST prEN 300 132-3 V2.1.13:2021
2 Draft ETSI EN 300 132-3 V2.1.13 (2021-04)
Reference
REN/EE-0265
Keywords
environment, interface, power supply
ETSI
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ETSI
---------------------- Page: 4 ----------------------
oSIST prEN 300 132-3 V2.1.13:2021
3 Draft ETSI EN 300 132-3 V2.1.13 (2021-04)
Contents

Intellectual Property Rights ................................................................................................................................ 5

Foreword ............................................................................................................................................................. 5

Modal verbs terminology .................................................................................................................................... 6

1 Scope ........................................................................................................................................................ 7

2 References ................................................................................................................................................ 7

2.1 Normative references ......................................................................................................................................... 7

2.2 Informative references ........................................................................................................................................ 8

3 Definition of terms, symbols and abbreviations ....................................................................................... 8

3.1 Terms .................................................................................................................................................................. 8

3.2 Symbols .............................................................................................................................................................. 9

3.3 Abbreviations ................................................................................................................................................... 10

4 Power interface "A3" .............................................................................................................................. 10

5 DC interface requirements ...................................................................................................................... 11

5.0 General ............................................................................................................................................................. 11

5.1 Nominal voltage ............................................................................................................................................... 11

5.2 Normal service voltage range at interface "A3" ............................................................................................... 11

5.3 Normal operating voltage range at interface "A3" ........................................................................................... 12

5.4 Reference test voltage (U ) at interface "A3" ................................................................................................... 12

5.5 Abnormal service voltage ranges at interface "A3" .......................................................................................... 12

6 Abnormal conditions: Voltage variations, voltage dips, short interruptions and voltage surges at

interface "A3" ......................................................................................................................................... 13

6.0 General ............................................................................................................................................................. 13

6.1 Voltage variations............................................................................................................................................. 13

6.2 Voltage dips...................................................................................................................................................... 14

6.3 Short interruptions ............................................................................................................................................ 14

6.4 Voltage surges .................................................................................................................................................. 15

7 DC Supply protection ............................................................................................................................. 16

8 Maximum steady state current I , in the normal service voltage range ................................................. 16

9 Inrush current on connection to interface "A3" ...................................................................................... 17

9.1 Limits ............................................................................................................................................................... 17

9.2 Measurements ................................................................................................................................................... 18

10 Installation and Cabling, Earthing and Bonding .................................................................................... 19

11 Electrical Safety requirements ................................................................................................................ 19

12 EMC requirements at the input of ICT equipment ................................................................................. 20

Annex A (informative): Power supply considerations ......................................................................... 21

Annex B (informative): Identification of interface "A3" .................................................................... 22

Annex C (informative): Calculation of the extreme DC voltage range at interface "A3" ............... 23

Annex D (informative): Guide for defining inrush current energy, measuring inrush current

and test generator peak inrush current drive capability............................ 24

D.0 General ................................................................................................................................................... 24

D.1 Measurement .......................................................................................................................................... 24

D.2 Test generator peak inrush current drive capability ............................................................................... 25

ETSI
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oSIST prEN 300 132-3 V2.1.13:2021
4 Draft ETSI EN 300 132-3 V2.1.13 (2021-04)

D.3 Example of inrush current waveform ..................................................................................................... 25

Annex E (informative): Dimensioning of over-current protective devices ........................................ 27

Annex F (informative): Details of the voltage transient measurement in the most common

case of distribution and protective devices .................................................. 28

Annex G (informative): Diagram of voltage ranges and values at the interface "A3" .................... 30

History .............................................................................................................................................................. 31

ETSI
---------------------- Page: 6 ----------------------
oSIST prEN 300 132-3 V2.1.13:2021
5 Draft ETSI EN 300 132-3 V2.1.13 (2021-04)
Intellectual Property Rights
Essential patents

IPRs essential or potentially essential to normative deliverables may have been declared to ETSI. The information

pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found

in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in

respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web

server (https://ipr.etsi.org/).

Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee

can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web

server) which are, or may be, or may become, essential to the present document.
Trademarks

The present document may include trademarks and/or tradenames which are asserted and/or registered by their owners.

ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no

right to use or reproduce any trademark and/or tradename. Mention of those trademarks in the present document does

not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks.

Foreword

This draft European Standard (EN) has been produced by ETSI Technical Committee Environmental Engineering (EE),

and is now submitted for the combined Public Enquiry and Vote phase of the ETSI standards EN Approval Procedure.

The present document concerns the requirements for the interface between Information and Communication

Technology (ICT) equipment and its power supply. It includes requirements relating to its stability and measurement.

Various other references and detailed measurement and test arrangements are contained in informative annexes.

The introduced interface up to 400 V Direct Current (DC) is considering power consumption increase and equipment

power density increase in order to get higher energy efficiency with less material than with low voltage -48 VDC or

permanent AC powering solution.

The up to 400 VDC interface could also simplify the use of renewable energy source with DC output such as

photovoltaic generator.

The present document is part 3 of a multi-part deliverable covering Environmental Engineering (EE); Power supply

interface at the input to Information and Communication Technology ICT equipment, as identified below:

Part 1: "Alternating Current (AC)";
Part 2: "-48 V Direct Current (DC)";
Part 3: "Up to 400 V Direct Current (DC)";
Part 4: "Up to 400 V Direct Current (DC) and Alternating Current (AC)".
Proposed national transposition dates
Date of latest announcement of this EN (doa): 3 months after ETSI publication
Date of latest publication of new National Standard
or endorsement of this EN (dop/e): 6 months after doa

Date of withdrawal of any conflicting National Standard (dow): 6 months after doa

ETSI
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oSIST prEN 300 132-3 V2.1.13:2021
6 Draft ETSI EN 300 132-3 V2.1.13 (2021-04)
Modal verbs terminology

In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and

"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of

provisions).

"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.

ETSI
---------------------- Page: 8 ----------------------
oSIST prEN 300 132-3 V2.1.13:2021
7 Draft ETSI EN 300 132-3 V2.1.13 (2021-04)
1 Scope

The present document contains requirements and measurements methods for the physical interface "A3" that is situated

between the power supply system(s) and the power consuming ICT equipment:

• the nominal voltage at power interface "A3" of ICT equipment defined in the present document is DC voltage up

to 400 V;

• the output performance of the power equipment including the cable network at the interface "A3";

• the input of the ICT equipment connected to interface "A3".

The DC power can be supplied by a DC output power system e.g. via on-grid AC rectifiers, from DC/DC converters in

solar systems, fuel cells, standby generators including a battery backup.

The present document aims at providing compatibility at interface "A3" between the power supply equipment and different

ICT equipment (including/monitoring, cooling system, etc.) connected to the same power supply.

The requirements are defined for the purpose of the present document:

• to identify a power supply system with the same characteristics for all ICT equipment defined in the area of

application; the area of application may be any location where the interface "A3" is used i.e.

telecommunication centres, Radio Base Stations, datacentres and customer premises;

• to facilitate interworking of different loads;
• to facilitate the standardization of power supply systems for ICT equipment;

• to facilitate the installation, operation and maintenance in the same network of ICT equipment and systems

from different origins.

• to secure robustness against temporary voltage deviations and transients during abnormal conditions

General requirements for safety and EMC are out of the scope of the present document series unless specific

requirement not defined in existing safety or EMC standards.
2 References
2.1 Normative references

References are either specific (identified by date of publication and/or edition number or version number) or

non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the

referenced document (including any amendments) applies.

Referenced documents which are not found to be publicly available in the expected location might be found at

https://docbox.etsi.org/Reference.

NOTE: While any hyperlinks included in the present clause were valid at the time of publication, ETSI cannot

guarantee their long term validity.

The following referenced documents are necessary for the application of the present document.

[1] IEC 60947-2: "Low-voltage switchgear and controlgear - Part 2: Circuit-breakers".

[2] IEC 60269-1: "Low-voltage fuses - Part 1: General requirements".

[3] IEC 61000-4-5: "Electromagnetic compatibility (EMC) - Part 4-5: Testing and measurement

techniques - Surge immunity test".
ETSI
---------------------- Page: 9 ----------------------
oSIST prEN 300 132-3 V2.1.13:2021
8 Draft ETSI EN 300 132-3 V2.1.13 (2021-04)

[4] IEC 61000-4-29: "Electromagnetic compatibility (EMC) - Part 4-29: Testing and measurement

techniques - Voltage dips, short interruptions and voltage variations on d.c. input power port

immunity tests".

[5] IEC 60898-2: "Electrical accessories - Circuit-breakers for overcurrent protection for household

and similar installations - Part 2: Circuit-breakers for AC and DC operation".

[6] ETSI EN 301 605 (V1.1.1) (2013): "Environmental Engineering (EE); Earthing and bonding of

400 VDC data and telecom (ICT) equipment".

[7] Recommendation ITU-T L.1207 (2018): "Progressive migration of telecommunication/information

and communication technology site to 400 VDC sources and distribution".

[8] IEC 60364-4-41: "Low voltage electrical installations - Part 4-41: Protection for safety - Protection

against electric shock".

[9] EN 60445: "Basic and safety principle for man-machine interface, marking and identification-

Identification of equipment terminals, conductor terminations and conductors". (Produced by

CENELEC).

[10] Recommendation ITU-T L.1203 (2016): "Colour and marking identification of up to 400 VDC

power distribution for information and communication technology systems".
2.2 Informative references

References are either specific (identified by date of publication and/or edition number or version number) or

non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the

referenced document (including any amendments) applies.

NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee

their long term validity.

The following referenced documents are not necessary for the application of the present document but they assist the

user with regard to a particular subject area.

[i.1] ETSI EN 300 132-2: "Environmental Engineering (EE); Power supply interface at the input of

Information and Communication Technology (ICT) equipment; Part 2: -48 V Direct Current

(DC)".

[i.2] IEC 60050-601: "International Electrotechnical Vocabulary. Chapter 601: Generation,

transmission and distribution of electricity - General".

[i.3] ETSI EN 300 386: "Electromagnetic compatibility and Radio spectrum Matters (ERM);

Telecommunication network equipment; ElectroMagnetic Compatibility (EMC) requirements".

[i.4] EN 62368-1: "Audio/video, information and communication technology equipment - Part 1: Safety

requirements". (Produced by CENELEC).
3 Definition of terms, symbols and abbreviations
3.1 Terms
For the purposes of the present document, the following terms apply:

abnormal service voltage ranges: steady-state voltage ranges over which the ICT equipment will not be expected to

maintain normal service but will survive undamaged
area of application: any location where the interface "A3" is used

NOTE: i.e. telecommunication centres, Radio Base Stations, datacentres and customer premises

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oSIST prEN 300 132-3 V2.1.13:2021
9 Draft ETSI EN 300 132-3 V2.1.13 (2021-04)
customer premises: any location which is the sole responsibility of the customer

dual feeding system: independent power systems i.e. two separate power sources (A+B)

high-Ohmic distribution system: distribution system in which the equipment is connected separately to the battery

with added impedance

NOTE 1: The high impedance can be achieved with long cables and in some cases additional resistors are installed.

NOTE 2: With this distribution the undervoltage effects of fuse blowing transients are reduced on other equipment

connected to the battery.
ICT equipment: telecommunication or datacommunication equipment

independent power distribution: redundant power distribution i.e. dual feeders (A+B) from two separate power

sources (A+B) or a single power source

NOTE: Equipment having two power feeds is fitted with OR-ing devices or separate power supply units.

interface "A3": power interface at the input terminals of ICT, physical point, at which power supply is connected in

order to operate the ICT equipment
load unit: power consuming equipment, that is part of a system block

nominal voltage: value of the voltage by which the electrical installation or part of the electrical installation is

designated and identified.

NOTE: This definition is based on nominal voltage defined in IEC 60050-601 [i.2].

normal operating condition: typical environmental and powering conditions for operation of ICT equipment, power

supply, power distribution and battery

normal operating voltage: typical value of the voltage at "A3" interface within the normal operating voltage range

normal operating voltage range: voltage range at "A3" interface where the system operates most of the time, e.g. in

general linked to battery floating voltage

normal service: service mode where ICT equipment operates within its specification

normal service voltage range: range of the steady-state voltage at the "A3" interface over which the equipment will

maintain normal service.

NOTE: In general this wider than the normal operating voltage range as it includes a part of the battery discharge

voltage range.

operating voltage: value of the voltage under normal conditions, at a given instant and a given point ("A3" interface) of

the system

power supply network: network interconnecting the power source and the ICT equipment

reference test voltage: voltage used as a reference to define the test voltage in the present document

NOTE: The test voltage may be also a percentage of this voltage.

system block: functional group of ICT equipment depending for its operation and performance on its connection to the

same power supply

telecommunication centre: any location where ICT equipment is installed and is the sole responsibility of the operator

3.2 Symbols
For the purposes of the present document, the following symbols apply:
Ω ohm
k Ω Kilo ohm
°C Celsius
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oSIST prEN 300 132-3 V2.1.13:2021
10 Draft ETSI EN 300 132-3 V2.1.13 (2021-04)
A Ampere
di/dt derivative of a considered current versus time
Hz Hertz
I current
Im maximum steady state current drain at 260 VDC at interface "A3"

I maximum steady state current drain in the abnormal service voltage range at interface "A3"

mss
I current rating of the over-current protective device
I peak inrush current at interface "A3"
maximum steady state current drain at U at interface "A3"
IUT T
m meter
ms milli seconds
s seconds
T time duration of the inrush current pulse at 50 % of Ip
U output voltage range of a generator
Reference Test Voltage
V Volt
W Watt
µs micro seconds
3.3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
AC Alternating Current
CB Circuit Breaker
CLD Current Limiting Device
DC Direct Current
DC/DC DC converter
EE Environmental Engeneering
EMC ElectroMagnetic Compatibility
EN European Standard
ERM Electromagnetic compatibility and Radio spectrum Matters
EUT Equipment Under Test
ICT Information and Communication Technology
N Neutral conductor
PE Protective Earth
VAC Volts Alternating Current
VDC Volts Direct Current
VRLA Valve Regulated Lead Acid
4 Power interface "A3"

The power supply interface "A3" in figure 1, is a physical point to which all the requirements are related. This point is

situated at the power input terminals of the ICT equipment.

Examples of configurations in which interface "A3" is identified are given in annex B.

Basic rules for marking of conductors and connectors shall be in accordance with EN 60445 [9].

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oSIST prEN 300 132-3 V2.1.13:2021
11 Draft ETSI EN 300 132-3 V2.1.13 (2021-04)
(+)
telecom/datacom (ICT)
(-)
Power suppl y
equipment
system block
(+) Positive DC terminal.
(-) Negative DC terminal.
PE Protective Earth.
Figure 1: General identification of the interface "A3"
5 DC interface requirements
5.0 General

The definition of the DC interface voltages ranges and typical operating voltage values are illustrated in annex G.

5.1 Nominal voltage

The selected battery in general determines this nominal voltage, the operating voltage and the normal service voltage

range in the system.

NOTE 1: For example, 336 V is a nominal voltage defined with 168 lead-acid battery cells multiplied by the

nominal cell voltage 2 V. This nominal DC voltage is equivalent to 48 V multiplied by 7. It allows the use

of existing 48 V battery rack (e.g. Lithium battery racks). There may be other nominal voltage defined

with different number of cells e.g. 156 lead-acid battery cells that lead to 312 V nominal voltage. Other

battery technologies are possible in the future and will influence nominal voltage as well. For detailed

calculation, refer to the annex C.

NOTE 2: In an architecture with a boost converter down-stream the battery, the operating voltage is linked to the

Nominal Voltage determined in clause 5.1 provided that converter output voltage is within the Normal

Service Voltage range.
5.2 Normal service voltage range at interface "A3"

The normal service voltage range at powering interface "A3" of ICT equipment shall be as follows:

• minimum voltage: 260 VDC;
• maximum voltage: 400 VDC.

NOTE 1: The voltage at the output of the power supply takes into account the voltage drop in the cable at

maximum steady current Im and/or the maximum battery charge to stay in the normal service voltage

range at the interface "A3" as explained in annexes A, B, C and G.

NOTE 2: For examples on how to calculate normal service voltage range, refer to annex C.

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oSIST prEN 300 132-3 V2.1.13:2021
12 Draft ETSI EN 300 132-3 V2.1.13 (2021-04)
5.3 Normal operating voltage range at interface "A3"

The normal operating voltage range at interface "A3" is defined by the voltage levels where the system will operate

most of the time under normal operating conditions; this range shall be within the normal service voltage range.

The normal operating voltage is a typical voltage inside the normal operating voltage range.

NOTE 1: Examples of normal operating voltages are 354 V and 380 V.

354 V corresponds to 156 VRLA cells in floating mode (351 V to 359 V with 2,25 V to 2,30 V per cell)

and with no voltage drop in the power distribution.

380 V corresponds to 168 VRLA cells in floating mode (378 V to 386 V with 2,25 V to 2,30 V per cell)

and with no voltage drop in the power distribution.

NOTE 2: For examples on how to calculate normal operating voltage range, refer to annex C.

5.4 Reference test voltage (U ) at interface "A3"
The reference test voltage (U ) for ICT equipment is defined at:
U = 365 V ± 15 V

NOTE: The powering solution should work in any site even with very long power cables i.e. U at the input of

ICT equipment is lower than power supply output. For constant power ICT equipment, the current is

increasing as a function of decreasing voltage.
5.5 Abnormal service voltage ranges at interface "A3"

The ICT equipment may be subjected to steady state voltage out of the normal service voltage range. Limits of

abnormal service voltage range are defined as follows:
• 0 V < U < 260 V
• 400 V < U < 410 V for 1 s
• 410 < U < 420 V for maximum 10 ms

For example, it may be generated from undervoltage or overvoltage at battery end of discharge cycle or battery end of

charge or rectifier regulation/control failures.

ICT equipment with interface "A3" shall not suffer any damage when subjected to the abnormal voltage range.

After the restoration of the supply from the abnormal service voltage range to the normal service voltage range, the ICT

equipment shall fulfil the following performance criteria:
• the ICT equipment shall not suffer any damage;

• the ICT equipment shall be able to automatically resume operation according to its specifications when the

voltage comes back into the normal service voltage range.

NOTE: The second criterion implies that abnormal service voltage should not lead to the disconnection of power

supply units e.g. by causing c
...

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