SIST EN 300 132-2 V2.1.2:2006

• Abstract:

  The present document contains requirements for:; - the output performance of the direct current (dc) power equipment at the interface "A";; - the input of the telecommunications equipment connected to interface "A" powered by dc.; The dc voltage at interface "A" may be derived from the AC primary supply. The dc supply may incorporate a backup battery. If any other equipment e.g. datacom equipment, are connected to interface "A" in parallel to telecommunications equipment, all requirements addressed in clause 4 of the present document must be fulfilled. The present document aims at providing compatibility between the power supply equipment and the power consuming telecommunications equipment, and also between different system blocks connected to the same power supply. ; NOTE 1: The present document is applicable only to -48 V dc power supply interfaces. However, during a transitional period, other dc voltages may be used in existing installations. Annex A gives guidance on working in conjunction with existing -60 V dc supply systems.; The power supply interface, interface "A", is a physical point to which all the requirements are related (see figure 1).; This point is situated between the power supply system(s) and the power consuming telecommunications equipment.; NOTE 2: Interface "A" is located at the power terminals of the telecommunications equipment. Subject to the installation preconditions this point may be located at any other point between the power supply system and the telecommunications equipment by mutual agreement of the relevant parties.; The requirements at interface "A" apply to:; - the output of the power supply equipment or power supply installation of telecommunications centres;; - the power supply input of telecommunications equipment installed at telecommunication centres;; - telecommunications equipment, installed in customers' premises, whose dc interface "A" is also used by equipment requiring a supply to this specification.; NOTE 3: Normally there is more than one load unit connected to interface "A". In these cases, interface "A" will undergo further restrictions with respect to noise limits or other disturbances specified in clause 4.8.; NOTE 4: Disturbances on the power supply interface "A" relating to the continuous wave phenomena below 20 kHz are covered within the present document.; NOTE 5: An example of a configuration in which interface "A" is identified is given in annex D.

• Status: Published
• Publication Date: 31-Jan-2006
• ICS: 19.040 - Environmental testing
• ICS: 33.050.01 - Telecommunication terminal equipment in general
• Technical Committee: SS EIT - Technical Board for the electrotechnical, information technology and telecommunications fields
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Feb-2006
• Due Date: 01-Feb-2006
• Completion Date: 01-Feb-2006
• Ref Project: ETSI EN 300 132-2 V2.1.2 (2003-09) - Environmental Engineering (EE); Power supply interface at the input to telecommunications equipment; Part 2: Operated by direct current (dc)

Overview

SIST EN 300 132-2 V2.1.2:2006 provides the standardized requirements for the power supply interface at the input to telecommunications equipment, specifically when operated by direct current (dc). The standard is essential for ensuring compatibility and stable operation between dc power supply equipment and dc-powered telecommunications devices at interface "A", which commonly uses a nominal -48 V dc supply. This interface is crucial for network equipment reliability in telecommunications centers and customer premises, supporting seamless integration and maintenance across various systems.

Key Topics

• Output Performance Requirements
  Specifies the expected characteristics for the dc power equipment output at interface "A", including voltage levels, regulation, and current handling.

• Input Requirements for Telecom Equipment
  Defines acceptable voltage ranges, protection measures, and current draw limits for telecommunications equipment connected to interface "A".

• Voltage Ranges and Recovery

  • Nominal Voltage: -48 V dc (with transitional provisions for -60 V dc in legacy installations)
  • Normal Service Range: Typically -40.5 V to -57 V dc, ensuring full operational capability
  • Abnormal Service Range: Equipment must withstand temporary deviations without damage (0 V to -40.5 V dc or -57 V to -60 V dc)
  • Includes criteria for automatic recovery following abnormal conditions or transients

• Noise and Disturbance Limits

  • Specifications for conducted immunity and emissions at interface "A", focusing on narrowband and wideband noise below 20 kHz
  • Test methods and limit values help prevent disruption to sensitive telecommunications services

• Inrush and Surge Current Limits

  • Defines testing and measurement procedures for inrush current upon connection, safeguarding both equipment and protective devices (such as circuit breakers and fuses)

• Parallel Loads and System Compatibility

  • Requirements ensure that multiple devices (e.g., additional datacom equipment) connected to the same dc interface meet all system-wide criteria

Applications

Adhering to SIST EN 300 132-2 V2.1.2:2006 ensures:

• Safe and Reliable Power Distribution

  • Supports uninterrupted telecommunications operations within central offices, exchanges, and at customer sites
  • Defines mechanisms for power protection and restoration following supply disturbances

• Interoperability in Mixed-Vendor Environments

  • Facilitates the integration of telecommunications equipment from different manufacturers, simplifying installation and upgrades

• Compliance with Industry Practices

  • Provides a harmonized approach to dc power interface design, crucial for telecom and datacom infrastructure expansion and maintenance

• Noise Control and Electromagnetic Compatibility

  • Ensures that voltage fluctuations and electromagnetic disturbances at interface "A" do not compromise critical voice and data traffic

• Legacy System Transition

  • Offers guidance on integrating new equipment into existing -60 V dc powered systems, relevant for operators in transition phases

Related Standards

Several international standards are referenced to ensure full compliance and promote compatibility across systems:

• IEC 60269-1: Low-voltage fuses - general requirements, supporting correct selection of circuit protection elements
• EN 60934: Circuit-breakers for equipment
• ETSI EN 300 253: Earthing and bonding of telecommunication equipment within centers
• ITU-T Recommendations (Q.551, Q.552, Q.553, Q.554): Transmission characteristics for various telecommunication interfaces
• ITU-T O.41: Psophometer for noise measurement in telephone-type circuits

Keywords

Power supply interface, telecommunications equipment, direct current (dc), -48 V dc, dc power supply standard, interface "A", equipment compatibility, dc noise limits, inrush current, telecommunication center, ETSI, SIST, electrical protection, system interoperability, environmental engineering standard.

SLOVENSKI STANDARD
01-februar-2006
Okoljski inženiring (EE) – Napajalni vmesnik na vhodu v telekomunikacijsko
opremo – 2. del: Obratovanje z enosmerno napetostjo (dc)
Environmental Engineering (EE); Power supply interface at the input to
telecommunications equipment; Part 2: Operated by direct current (dc)
Ta slovenski standard je istoveten z: EN 300 132-2 Version 2.1.2
ICS:
19.040 Preskušanje v zvezi z Environmental testing
okoljem
33.050.01 Telekomunikacijska Telecommunication terminal
terminalska oprema na equipment in general
splošno
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

European Standard (Telecommunications series)

Environmental Engineering (EE);
Power supply interface at the input to
telecommunications equipment;
Part 2: Operated by direct current (dc)

2 ETSI EN 300 132-2 V2.1.2 (2003-09)

Reference
REN/EE-02008[2]
Keywords
Interface, power supply
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ETSI
3 ETSI EN 300 132-2 V2.1.2 (2003-09)
Contents
Intellectual Property Rights.4
Foreword.4
1 Scope .5
2 References.6
3 Definitions, symbols and abbreviations .7
3.1 Definitions.7
3.2 Symbols.7
3.3 Abbreviations.8
4 Requirements.8
4.1 Nominal voltage.8
4.2 Normal service voltage range at interface "A" .8
4.3 Abnormal service voltage range at interface "A" .8
4.3.1 Abnormal service voltage under steady-state conditions.8
4.3.2 Recovery from steady state abnormal voltage .8
4.3.3 Voltage transients.9
4.3.4 Recovery from voltage transients .9
4.4 Voltage changes due to the regulation of the power supply.9
4.4.1 Test conditions.9
4.4.2 Performance criteria.9
4.5 Supply protection at interface "A".10
4.6 Maximum current drain following abnormal service .10
4.7 Surge current on connection of interface "A".10
4.7.1 Limits.10
4.7.2 Measurements.11
4.8 Conducted immunity requirements of the telecommunications equipment at interface "A".11
4.8.1 Immunity to narrowband noise .12
4.8.2 Immunity to wideband noise.13
4.9 Conducted emissions requirements of the telecommunications equipment at interface "A".14
4.9.1 Emissions of narrow-band noise.14
4.9.2 Emission of wideband noise .15
5 Earthing and bonding .15
6 Electrical safety requirements .16
7 EMC requirements.16
Annex A (informative): -60 V systems.17
dc
Annex B (informative): Guide for measuring inrush current and for transferring the
recorded pulses onto the limit chart.18
B.1 Measurement.18
B.2 Pulse waveform transformation.19
Annex C (informative): Test arrangements for the injection of electrical noise at interface
"A".20
Annex D (informative): Identification of interface "A".21
Annex E (informative): Bibliography.22
History .23

ETSI
4 ETSI EN 300 132-2 V2.1.2 (2003-09)
Intellectual Property Rights
IPRs essential or potentially essential to the present document 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 (http://webapp.etsi.org/IPR/home.asp).
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.
Foreword
This European Standard (Telecommunications series) has been produced by ETSI Technical Committee Environmental
Engineering (EE).
The present document concerns the requirements for the interface between telecommunications equipment and its
power supply, and includes requirements relating to its stability and measurement. Various other references and detailed
measurement and test arrangements are contained in informative annexes.
The present document is part 2 of a multi-part deliverable covering Environmental Engineering (EE); Power supply
interface at the input to telecommunications equipment, as identified below:
Part 1: "Operated by alternating current (ac) derived from direct current (dc) sources";
Part 2: "Operated by direct current (dc)";
Part 3: "Operated by rectified current source, alternating current source or direct current source up to 400 V".

National transposition dates
Date of latest announcement of this EN (doa): 31 December 2003
Date of latest publication of new National Standard
or endorsement of this EN (dop/e): 30 June 2004
Date of withdrawal of any conflicting National Standard (dow): 30 June 2004

ETSI
5 ETSI EN 300 132-2 V2.1.2 (2003-09)
1 Scope
The present document contains requirements for:
- the output performance of the direct current (dc) power equipment at the interface "A";
- the input of the telecommunications equipment connected to interface "A" powered by dc.
The dc voltage at interface "A" may be derived from the AC primary supply. The dc supply may incorporate a backup
battery.
If any other equipment e.g. datacom equipment, are connected to interface "A" in parallel to telecommunications
equipment, all requirements addressed in clause 4 of the present document must be fulfilled.
The present document aims at providing compatibility between the power supply equipment and the power consuming
telecommunications equipment, and also between different system blocks connected to the same power supply.
NOTE 1: The present document is applicable only to -48 V power supply interfaces. However, during a
dc
transitional period, other dc voltages may be used in existing installations. Annex A gives guidance on
working in conjunction with existing -60 V supply systems.
dc
The power supply interface, interface "A", is a physical point to which all the requirements are related (see figure 1).
This point is situated between the power supply system(s) and the power consuming telecommunications equipment.
NOTE 2: Interface "A" is located at the power terminals of the telecommunications equipment. Subject to the
installation preconditions this point may be located at any other point between the power supply system
and the telecommunications equipment by mutual agreement of the relevant parties.
The requirements at interface "A" apply to:
- the output of the power supply equipment or power supply installation of telecommunications centres;
- the power supply input of telecommunications equipment installed at telecommunication centres;
- telecommunications equipment, installed in customers' premises, whose dc interface "A" is also used by
equipment requiring a supply to this specification.
NOTE 3: Normally there is more than one load unit connected to interface "A". In these cases, interface "A" will
undergo further restrictions with respect to noise limits or other disturbances specified in clause 4.8.
NOTE 4: Disturbances on the power supply interface "A" relating to the continuous wave phenomena below
20 kHz are covered within the present document.
NOTE 5: An example of a configuration in which interface "A" is identified is given in annex D.
ETSI
6 ETSI EN 300 132-2 V2.1.2 (2003-09)
telecommunications
equipment
DC power supply conductors
System block
Interface "A"
Figure 1: Identification of interface "A"
The purpose of the present document is:
- to use a power supply system with the same characteristics for all telecommunications equipment defined in
the area of application;
- to facilitate inter working of different (types of) load units;
- to facilitate the standardization of telecommunications equipment;
- to facilitate the installation, operation and maintenance in the same network of equipment and
telecommunications systems from different origins.
2 References
The following documents contain provisions which, through reference in this text, constitute provisions of the present
document.
• References are either specific (identified by date of publication and/or edition number or version number) or
non-specific.
• For a specific reference, subsequent revisions do not apply.
• For a non-specific reference, the latest version applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
http://docbox.etsi.org/Reference.
[1] IEC 60269-1: "Low-voltage fuses - Part 1: General requirements".
[2] EN 60934: "Circuit-breakers for equipment (CBE)".
[3] ETSI EN 300 253: "Environmental Engineering (EE); Earthing and bonding of telecommunication
equipment in telecommunication centres".
[4] ITU-T Recommendation Q.551: "Transmission characteristics of digital exchanges".
[5] ITU-T Recommendation Q.552: "Transmission characteristics at 2-wire analogue interfaces of
digital exchanges".
[6] ITU-T Recommendation Q.553: "Transmission characteristics at 4-wire analogue interfaces of
digital exchanges".
ETSI
7 ETSI EN 300 132-2 V2.1.2 (2003-09)
[7] ITU-T Recommendation Q.554: "Transmission characteristics at digital interfaces of digital
exchanges".
[8] ITU-T Recommendation O.41: "Psophometer for use on telephone-type circuits".
3 Definitions, symbols and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
abnormal voltage range: range of steady-state voltage over which the equipment will not be expected to maintain
normal service but will survive undamaged
customer premises: any location which is the sole responsibility of the customer
interface "A": terminals at which the power supply is connected to the system block
NOTE 1: See also figure 1.
NOTE 2: This is a functional definition and not an exact depiction of the physical location.
load unit: power-consuming equipment, that is part of a system block
maximum continuous input current: maximum continuous input current, stated by the manufacturer, for a
fully-equipped equipment under test connected to interface "A", at nominal voltage (accordance clause 4.7.1 of
EN 300 132-2)
normal service: service mode where telecommunications equipment operates within its specification
normal service voltage range: range of steady-state voltages over which the equipment will maintain normal service
nominal voltage: nominal value of the voltage that designates the type of supply
power supply: power source to which telecommunications equipment is intended to be connected
system block: functional group of equipment depending for its operation and performance on its connection to the same
power supply
NOTE: A system block may consist of equipment or a functional group of equipment. Different examples of
configurations at interface "A" are given in annex D.
telecommunication centre: location where telecommunications equipment is installed and which is the sole
responsibility of the operator
3.2 Symbols
For the purposes of the present document, the following symbols apply:
I instantaneous surge current (see clause 4.7.1)
t
I maximum continuous input current
m
L inductance of inductive element of LISN
R resistance of resistive element of LISN
t time
Z capacitive impedance of immunity measurement circuit
c
Z resistive impedance of immunity measurement circuit
m
ETSI
8 ETSI EN 300 132-2 V2.1.2 (2003-09)
3.3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
dc direct current (also when used as a suffix to units of measurement)
EUT Equipment Under Test
LISN Line Impedance Stabilization Network
rms root mean square (also when used as a suffix to units of measurement)
4 Requirements
4.1 Nominal voltage
The nominal value of the voltage at interface "A" shall be -48 V (positive conductor is connected to earth).
dc
NOTE 1: In most cases the voltage of interface "A" will be complemented by a 24 cell lead-acid battery.
NOTE 2: During a transitional period, other dc voltages may be used in existing installations. Annex A gives
guidance on merging equipment with existing -60 V supply systems.
dc
4.2 Normal service voltage range at interface "A"
The normal service voltage range for the -48 V nominal supply at interface "A" shall be -40,5 V to -57,0 V .
dc dc dc
NOTE 1: The minimum voltage is based on the voltage drop in the distribution network and a battery cell end of
discharge voltage.
NOTE 2: The voltages specified are measured at interface "A". It should be noted that if interface "A" is at any
point other than the telecommunications equipment interface there will be a voltage drop between
interface "A" and the equipment terminals.
NOTE 3: When the voltage is in the range -40,5 V to -44,0 V it is recognized that there may be a slight
dc dc
degradation of service performance.
4.3 Abnormal service voltage range at interface "A"
4.3.1 Abnormal service voltage under steady-state conditions
Telecommunications equipment operated at -48 V shall not suffer any damage when subjected to the following
dc
voltage ranges:
0,0 V to -40,5 V and
dc dc
-57,0 V to -60,0 V
dc dc
4.3.2 Recovery from steady state abnormal voltage
Following the restoration of the supply to the normal voltage range, the power conversion and management systems on
the l
...