Amendment 1 - Low voltage surge protective devices - Part 21: Surge protective devices connected to telecommunications and signalling networks - Performance requirements and testing methods

Amendement 1 - Parafoudres basse tension - Partie 21: Parafoudres connectés aux réseaux de signaux et de télécommunications - Prescriptions de fonctionnement et méthodes d'essais

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Publication Date
24-Apr-2008
Current Stage
PPUB - Publication issued
Start Date
25-Apr-2008
Completion Date
25-Apr-2008
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IEC 61643-21:2000/AMD1:2008 - Amendment 1 - Low voltage surge protective devices - Part 21: Surge protective devices connected to telecommunications and signalling networks - Performance requirements and testing methods
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IEC 61643-21
Edition 1.0 2008-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
AMENDMENT 1
AMENDEMENT 1
Low voltage surge protective devices –
Part 21: Surge protective devices connected to telecommunications and
signalling networks – Performance requirements and testing methods
Parafoudres basse tension –
Partie 21: Parafoudres connectés aux réseaux de signaux et de
télécommunications – Prescriptions de fonctionnement et méthodes d’essais
IEC 61643-21 A1:2008
---------------------- Page: 1 ----------------------
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---------------------- Page: 2 ----------------------
IEC 61643-21
Edition 1.0 2008-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
AMENDMENT 1
AMENDEMENT 1
Low voltage surge protective devices –
Part 21: Surge protective devices connected to telecommunications and
signalling networks – Performance requirements and testing methods
Parafoudres basse tension –
Partie 21: Parafoudres connectés aux réseaux de signaux et de
télécommunications – Prescriptions de fonctionnement et méthodes d’essais
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX
ICS 29.240; 29.240.10 ISBN 2-8318-9731-9
---------------------- Page: 3 ----------------------
– 2 – 61643-21 Amend. 1 © IEC:2008
FOREWORD

This amendment has been prepared by subcommittee 37A: Low-voltage surge protective

devices, of IEC technical committee 37: Surge arresters.
The text of this amendment is based on the following documents:
FDIS Report on voting
37A/200/FDIS 37A/201/RVD

Full information on the voting for the approval of this amendment can be found in the report

on voting indicated in the above table.

The committee has decided that the contents of this amendment and the base publication will

remain unchanged until the maintenance result date indicated on the IEC web site under

"http://webstore.iec.ch" in the data related to the specific publication. At this date, the

publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
_____________
---------------------- Page: 4 ----------------------
61643-21 Amend. 1 © IEC:2008 – 3 –
Page 3
CONTENTS
Delete, on page 5, the title of Annexes B and C, and replace each by “Void”.
Add the following new Annexes D and E:

Annex D (informative) Measurement accuracy ..................................................................17

Annex E (informative) Determination of let-through current (I ) ......................................18

Page 9
FOREWORD
Delete the references to the annexes.
Page 15

Replace the existing Figures 1a, 1b, 1c, 1d, 1e and 1f with the following new figures:

SPD
(V)
IEC 549/08
Figure 1a – Two-terminal SPD
SPD
SPD
(V, I)
(V)
C X2
IEC 550/08
IEC 551/08
Figure 1b – Three-terminal SPD Figure 1c – Three-terminal SPD
X1 Y1
SPD
(V, I)
X2 Y2
X1 Y1
SPD
(V, I)
IEC 552/08
IEC 553/08
Figure 1d – Four-terminal SPD Figure 1e – Five-terminal SPD
---------------------- Page: 5 ----------------------
– 4 – 61643-21 Amend. 1 © IEC:2008
SPD
(V, I )
IEC 554/08
The common terminal C may not be provided.
Figure 1f – Multi-terminal SPD
---------------------- Page: 6 ----------------------
61643-21 Amend. 1 © IEC:2008 – 5 –
Page 17
1.3 Use of this standard
Replace the existing fifth paragraph by the following:

Subclause 5.2.3 provides transmission tests that SPDs may need to conform to, depending on

their communication and signalling application. Selection of the applicable transmission tests

from 5.2.3 shall be made, based on the intended application of the SPDs. Table 1 provides

general guidance on how to select the applicable transmission tests.
Delete the last line of this subclause.
Replace, on page 19, the existing Table 1 with the following new Table 1:
Table 1 – General SPD requirements
Test Sub-
4 Requirement – Test Type of SPD
series clause
1 General test 6.1
Identification and
documentation 6.1.1 A A A A A A
Marking 6.1.2 A A A A A A
Transmission tests 6.2.3
Capacitance 6.2.3.1 A O O O A O
Insertion loss 6.2.3.2 O A A A O A
Return loss 6.2.3.3 O O O A O O
Longitudinal balance 6.2.3.4 O O O A O O
Bit Error Ratio (BER) 6.2.3.5 O O O O O O
Near-end crosstalk (NEXT) 6.2.3.6 O O O A O O
Mechanical tests 6.3
Terminals and connectors 6.3.1 A A A A A A
General testing procedure 6.3.1.1 A A A A A A
Terminals with screws 6.3.1.2 A A A A A A
Screwless terminals 6.3.1.3 A A A A A A
Insulating pierced
connections 6.3.1.4 A A A A A A
Pull-out-test on SPD
terminals designed for
single-core conductors 6.3.1.4.1A A A A A A
Pull-out-test on SPD
terminals designed for multi-
core cables and cords 6.3.1.4.2 A A A A A A
Mechanical strength
(mounting) 6.3.2 A A A A A A
SPD with only voltage-
limiting function
SPD with both voltage-
limiting and current-
limiting functions
SPD with voltage-
limiting function and
linear component
between its terminals
SPD having both
voltage-limiting and
current-limiting
functions with enhanced
transmission
capabilities
SPD having only
voltage-limiting function
but intended for use in
extended range
environment
SPD having both
voltage-limiting and
current-limiting
functions but intends for
use in extended range
environment
---------------------- Page: 7 ----------------------
– 6 – 61643-21 Amend. 1 © IEC:2008
Table 1 (continued)
Test Sub-
4 Requirement – Test Type of SPD
series clause
Resistance to ingress of
solid objects and to harmful
ingress of water 6.3.3 A A A A A A
Protection against direct
contact 6.3.4 A A A A A A
Fire resistance 6.3.5 A A A A A A
Environmental tests
6.4
High temperature and
humidity endurance 6.4.1 O O O O A A
Environmental cycling with
impulse surges 6.4.2 O O O O A A
Environmental cycling with
a.c. surges 6.4.3 O O O O A A
2 Voltage limiting tests 6.2.1
Maximum continuous
operating voltage (Uc) 6.2.1.1 A A A A A A
Insulation resistance 6.2.1.2 A A A A A A
Impulse durability for
voltage limiting function 6.2.1.6 A A A A A A
Impulse-limiting voltage 6.2.1.3 A A A A A A
Impulse reset switching
types 6.2.1.4A A A A A A
AC durability for voltage
limiting function
6.2.1.5 O O O O O O
Blind spot test multi stage
SPD 6.2.1.8 A A A A A A
Overstressed fault mode 6.2.1.7 A A A A A A
3 Current limiting tests 6.2.2
Rated current 6.2.2.1 N.A. A A A N.A. A
Series resistance 6.2.2.2 N.A. A A A N.A. A
Current response time 6.2.2.3 N.A. A N.A. A N.A.
Current reset time 6.2.2.4 N.A. A N.A. A N.A.
Maximum interrupting A
voltage 6.2.2.5N.A. A N.A. A N.A.
Operating duty test 6.2.2.6 N.A. A N.A. A N.A.
AC durability for current A
1 3
limiting function 6.2.2.7N.A. A N.A. A N.A.
Impulse durability for A
1 3
current limiting function 6.2.2.8 N.A. A N.A. A N.A.
Acceptance tests
4 6.5 O O O O O O
A Applicable.
N.A. Not applicable.
O Optional.
For each category of test impulse a new set of samples can be used.

It is admissible to measure the impulse-limiting voltage 6.2.1.3 while testing impulse durability 4.2.1.6.

Test not applicable if there is a linear component between its terminals.
Each test series is carried out on three samples.
SPD with only voltage-
limiting function
SPD with both voltage-
limiting and current-
limiting functions
SPD with voltage-
limiting function and
linear component
between its terminals
SPD having both
voltage-limiting and
current-limiting
functions with enhanced
transmission
capabilities
SPD having only
voltage-limiting function
but intended for use in
extended range
environment
SPD having both
voltage-limiting and
current-limiting
functions but intends for
use in extended range
environment
---------------------- Page: 8 ----------------------
61643-21 Amend. 1 © IEC:2008 – 7 –
2 Normative references
Add the following new references:

IEC 61643-22:2004, Low-voltage surge protective devices – Part 22: Surge protection devices

connected to telecommunications and signalling networks – Selection and application

principles

ITU-T Recommendation K.55:2002, Overvoltage and overcurrent requirements for insulation

displacement connectors (IDC) terminations

ITU-T Recommendation K.65:2004, Overvoltage and overcurrent requirements for termination

modules with contacts for test ports or SPDs
ITU-T Recommendation O.9:1999, Measuring arrangements to assess the degree of
unbalance about earth
Delete, on page 21, the dates from the following references:
IEC 60529, IEC 61000-4-5, IEC 61083-1 and IEC 61643-1.
Delete the following reference:

ITU-T Recommendation K.17:1988, Tests on power-fed repeaters using solid-state devices in

order to check the arrangements for protection from external interference
3 Definitions

Replace, the existing definitions 3.8, 3.10, 3.14, 3.15 and 3.22 by the following new

definitions:
3.8
surge protective device
SPD

device that restricts the voltage of a designated port or ports, caused by a surge, when it

exceeds a predetermined level

NOTE 1 Secondary functions may be incorporated, such as a current-limiting to restrict a terminal current.

NOTE 2 Typically the protective circuit has at least one non-linear voltage-limiting surge protective component.

NOTE 3 An SPD is a complete assembly, having terminals to connect to the circuit conductors.

3.10
current limiting

action of an SPD, containing at least one non-linear current-limiting component, that causes

currents exceeding a predetermined value to be restricted
3.14
voltage clamping type SPD

SPD that has high shunt impedance and will have a continuous reduction in impedance with

increasing current in response to a voltage surge exceeding the threshold level of the SPD

NOTE Examples of components used in voltage clamping type SPDs: varistors (e.g. MOV) and avalanche

breakdown diodes (ABD).
3.15
voltage switching type SPD

SPD that has a high shunt impedance and will have a sudden and large reduction in

impedance in response to a voltage surge exceeding the threshold level of the SPD

NOTE Examples of components used in voltage switching type SPDs: air gaps, gas discharge tubes (GDT) and

thyristor surge suppressors (TSS).
---------------------- Page: 9 ----------------------
– 8 – 61643-21 Amend. 1 © IEC:2008
3.22
rated current

maximum current a current-limiting SPD can conduct continuously with no change in the

impedance of the current-limiting components
NOTE This is also applicable to linear series components.
Add, on page 29, the following new definition 3.32:
3.32
surge (telecommunications)

temporary excessive voltage or current, or both, coupled on a telecommunication line, from an

external electrical source
NOTE 1 Typical electrical sources are lightning and AC/DC power systems.

NOTE 2 Electrical source coupling can be one or more of the following; electric, magnetic, electromagnetic,

conductive.
4.1.1 Normal service conditions
Replace the existing text of 4.1.1 as follows:
4.1.1.1 Air pressure and altitude

Air pressure is 80 kPa to 106 kPa. These values represent an altitude of +2 000 m to –500 m

respectively.
4.1.1.2 Ambient temperature
• normal range: –5 °C to +40 °C

NOTE 1 This range normally addresses SPDs for indoor use. This corresponds to code AB4 in IEC 60364-5-51.

• extended range: –40 °C to +70 °C

NOTE 2 This range normally addresses SPDs for outdoor use in non weather-protected locations, class 3K7 in

IEC 60721-3-3.
• storage range: –40 °C to +70 °C
NOTE 3 All values beyond will be specified by the manufacturer.
4.1.1.3 Relative humidity
• normal range: 5 % to 95 %

NOTE 1 This range normally addresses SPDs for indoor use. This corresponds to code AB4 in IEC 60364-5-51.

• extended range: 5 % to 100 %

NOTE 2 This range normally addresses SPDs for outdoor use in non weather-protected locations (e.g. SPD is

contained in a weather proofed enclosure).
Page 31
4.3 SPD testing
Replace the first two paragraphs of this subclause by the following:

The SPDs covered by this standard shall be tested using the connections or terminations that

are used when the SPDs are installed in the field. Also, the measurements shall be made at

the connections or terminations of the SPDs. For those that are intended to be used with a

base or connector, that base or connector shall be part of the tests.

For telecommunication applications ITU-T gives requirements in the K-series for protection

holders (K.65) and termination modules (K.55).

When a base is used for testing, the measurements shall be made as close as possible to the

terminals of the SPD. Oscilloscopes used for measurements shall be in accordance with

IEC 61083-1.
---------------------- Page: 10 ----------------------
61643-21 Amend. 1 © IEC:2008 – 9 –
NOTE For oscilloscope settings, see Annex D.

SPDs of Figures 1c, 1e and 1f may have a common current path (including protective

The

components or just internal connections) that conducts the total impulse current.

manufacturer shall state the maximum value of impulse current for this current path. This

value of impulse current may be less than n times the maximum current capability of each line

terminal, where n equals the number of line terminals.

These SPDs shall have all of their line terminals tested simultaneously with respect to the

common terminal.
Page 35
5.2.1.1 Maximum continuous operating voltage (Uc)
Replace the existing text of this subclause by the following:

The manufacturer shall state the maximum continuous operating voltage for the SPD

appropriate for the application such as AC rms or DC.
Compliance shall be checked in accordance with 6.2.1.1.
Page 39
5.2.3 Transmission requirements
Replace the existing text of this subclause by the following:

The SPD, in addition to the requirements of 5.2.1 and 5.2.2, may need to conform to specific

requirements of 5.2.3 depending on its communication and signalling application (for

example, voice, data, and video). Table 1 provides guidance in the selection of applicable

transmission tests.
Page 47
6.2.1.3 Impulse-limiting voltage
Replace the first paragraph of this subclause by the following:

The SPDs shall be tested using one impulse selected from category C of Table 3 and applied

to the appropriate terminals. The current level shall be selected based on the energy

capability of the SPD as determined in the impulse durability test (see 6.2.1.6). Both impulse-

limiting voltage and impulse durability tests shall be performed with the same impulse. Values

listed in Table 3 are minimum requirements, other surge current ratings can be found in

standards e.g. ITU-T recommendations.
Replace the fourth paragraph of this subclause by the following:

Measure the voltage limitation for each impulse without load. The maximum voltage measured

at the appropriate terminals shall not exceed the specified voltage protection level (U ).

Sufficient time shall be allowed between impulses to prevent accumulation of heat. It is

understood that different SPDs will have different thermal characteristics, and consequently

will require different times between impulses.
For detail impulse recorders settings refer to Annex D.
---------------------- Page: 11 ----------------------
– 10 – 61643-21 Amend. 1 © IEC:2008
Page 49
Replace the existing Table 3 by the following new table:
Table 3 – Voltage and current waveforms for impulse-limiting voltage
Category Type of test Open-circuit Short-circuit Minimum Terminals to be
voltage current number of tested
applications
A1 Very slow rate 10 A, Not applicable X1 – C
≥ 1 kV
of rise Rate of rise from 0,1 A/µs to (NA) X2 – C
0,1 kV/µs to 2 A/μs, X1 – X2
100 kV/s ≥ 1 000 μs
(duration)
A2 AC Select a test from Table 5 Single cycle
B1 1 kV 100 A, 300
10/1000 10/1000
B2 Slow rate 1 kV to 4 kV 25 A to 100 A 300
of rise 10/700 5/300
B3 10 A to 100 A 300
≥ 1 kV
10/1 000
100 V/μs
C1 0,5 kV to < 2 kV 0,25 kA to < 1 kA 300
1,2/50 8/20
C2 2 kV to 10 kV 1 kA to 5 kA 10
1,2/50 8/20
Fast rate
of rise
C3 ≥ 1 kV 10 A to 100 A 300
10/1 000
1 kV/μs
D1 ≥ 1 kV 0,5 kA to 2,5 kA 2
10/350
High energy
0,6 kA to 2,0 kA
D2 5
≥ 1 kV
10/250

An open-circuit voltage different from 1 kV may be used. However, it must be sufficient to operate the SPD under

test.
X1 – X2 terminals shall be tested only if it is required.

NOTE 1 For the verification of U , one of the above impulse waveform of category C is mandatory and A, B and D

are optional. Unless otherwise specified, apply 5 positive and 5 negative pulses.

NOTE 2 For impulse reset, select test from category B, C and D. Unless otherwise specified, apply 3 positive and 3

negative pulses.

NOTE 3 For impulse durability measurement, one impulse waveform of category C is mandatory and A1, B and D

are optional.

NOTE 4 Values listed in Table 3 are minimum requirements; other surge current ratings are possible and can also

be found in other standards e.g. ITU-T K series – Recommendations.
Add the following text (including new Figure 16) immediately after Table 3:
Simultaneous surge on all protected conductors

Multi-line SPDs may use a common protective element for the ground return of the total

impulse current . Two examples are shown in Figure 16. All the protected lines shall have an

impulse current equal to total impulse current divided by number of lines. applied

simultaneously to verify that the common protective element had adequate current capability.

After this test the SPD shall not be degraded. This test also verifies that the internal

connections of the SPD have adequate current capability.
---------------------- Page: 12 ----------------------
61643-21 Amend. 1 © IEC:2008 – 11 –
Yn Xn Yn
Y2 X2 Y2
Y1 X1 Y1
C C C C
IEC 555/08 IEC 556/08
Star protection circuit Diode steering bridge
Key
X1, X2, Xn, line terminals 1 individual protective element
Y1, Y2, Yn, protected line terminals 2 common protective element
C common
Figure 16 – Examples of multi-line SPDs with a common protective element

The requirements of the current distributor (coupling network) shown in Figure 4 are as

follows:

– The coupling network shall not influence the test impulse. All parameters of the surge

waveform according to 4.4 apply to the output terminals of the coupling network.

– The front time and the pulse duration shall be verified at the output terminals of the

coupling network for surge voltages (open circuit) and surge currents (short-circuit).

– The surge waveform of the short-circuit current can be measured with the aid of a torroidal

current transformer or a current monitoring resistor.
– Preferably resistors should be used for the coupling network.

– The current sharing in each conductor of the distributor has to be tested individually with

the other conductors shorted before connection to the respective test specimen is made.

The results of this test does not mean that the currents will be equally shared when the

SPD is in the circuit.

– During the simultaneous test it will be verified that the common protective element was

exposed to the total impulse current without failure of any surge protective components.

---------------------- Page: 13 ----------------------
– 12 – 61643-21 Amend. 1 © IEC:2008
Page 49
6.2.1.4 Impulse reset
Replace, on page 51, the existing Table 4 with the following new table:
Table 4 – Source voltages and currents for impulse reset test
Open-circuit source voltage Short-circuit source current
V mA
12 500
24 500
48 260
97 80
135 200

The SPD may be connected in parallel by a series combination of a 135-150 Ω resistor and a

0,08 µF to 0,1 µF capacitor.
Tolerance (including ripple) + 10% -0%
6.2.1.5 AC durability
Replace the existing title by the following:
6.2.1.5 AC durability for voltage limiting function
Replace, on page 53, the existing Table 5 with the following new table:
Table 5 – Preferred values of currents for a.c. durability test
48 Hz-62 Hz Duration Number Test terminals
Short-circuit currents on of applications b
each tested terminal a
A s
rms
0,1 1 5 X1 – C
X2 – C
0,25 1 5
X1 – X2
0,5 1 5
0,5 30 1
1 1 5
1 1 60
2 1 5
2,5 1 5
5 1 5
10 1 5
20 1 5
Values listed in Table 5 are minimum requirements. .
b Different numbers of applications can be found in other standards e.g.
ITU-T K series - Recommendations
X1 – X2 terminals shall be tested only if required
---------------------- Page: 14 ----------------------
61643-21 Amend. 1 © IEC:2008 – 13 –
6.2.1.6 Impulse durability
Replace the existing title by the following:
6.2.1.6 Impulse durability for voltage limiting function
Replace the fifth paragraph of this subclause by the following:
For SPDs that have a common current path refer to 4.3.
Page 55
6.2.1.7 Overstressed fault mode
Replace the first two paragraphs of this subclause by the following:

The SPD shall be overstressed by impulse overstress and a.c. overstress currents. For tests

on the SPDs shown in Figures 1c, 1e and 1f, each pair of terminals (X1 – C and X2 – C) may

be tested separately. For SPD 1f select two terminals as a representative sample. Different

SPDs shall be tested for impulse and a.c. tests.

Then insulation resistance, voltage-limiting and series resistance (if applicable) tests shall be

performed to determine if the SPD has reached an acceptable overstressed fault mode as

described in 3.3. The SPD shall reach its overstressed fault mode in a safe manner without

causing a fire hazard, an explosion hazard, an electrical hazard or emission of toxic fumes.

Page 57
6.2.2.3 Current response time
Replace the first two paragraphs by the following:

The SPD shall be connected as shown in Figure 5. The source voltage shall be less than the

maximum interrupting voltage as specified by the manufacturer. The frequency shall be either

0 Hz (d.c.) or 50 Hz or 60 Hz, the choice being selected, according to the intended

application.

Devices shall be tested at appropriate temperatures with reference to 4.2. Sufficient time shall

be allowed between tests to ensure that devices cool back to testing temperature prior to

subsequent testing. Alternatively, separate devices can be used for each test to avoid waiting

for the cooling period. Rs or Rs1 and Rs2 shall be set to provide the desired prospective test

currents of Table 6. The response time of the current-limiting function at each test current

shall be recorded. The response time is the time from application of power until the current

falls to 10 % of the rated current. If the prospective test current exceeds the maximum current

capability of the current-limiting component(s), then the highest test current shall be the

maximum current capability of the current-limiting component(s).
Page 61
6.2.2.7 AC durability
Replace the existing title by the following:
6.2.2.7 AC durability for current limiting function
6.2.2.8 Impulse durability
Replace the existing title by the following:
6.2.2.8 Impulse durability for current limiting function
---------------------- Page: 15 ----------------------
– 14 – 61643-21 Amend. 1 © IEC:2008
Page 63
6.2.3.2 Insertion loss
Replace the existing Table 10 by the following new table:
Table 10 – Standard parameters for Figure 8
Frequency range Characteristic impedance Z
Cable types
300 Hz to 4 kHz 600 Twisted-pair
4 kHz to 250 MHz 100, 120 or 150 Twisted-pair
50 or 75 Coaxial
≤ 1 GHz
> 1 GHz 50 Coaxial
Page 65
6.2.3.4 Longitudinal balance

Replace the existing title and text of this subclause (including the existing Table 11) by the

following:
6.2.3.4 Longitudinal balance / Longitudinal conversion loss (LCL)

Longitudinal balance as calculated in the equation below is equivalent to longitudinal

conversion loss (LCL) as described in ITU-T O.9 (03.1999).

Figure 10 shows the connections for longitudinal balance testing of three- four- and five-

terminal SPDs. For four- and five-terminal SPDs, the test shall be carried out with switch S1

both open and closed. The longitudinal balance is the ratio of the applied longitudinal voltage

V and the resulting voltage V of the SPD under test expressed in dB, as follows:
s m
Longitudinal balance (dB) = 20 log (V / V )
s m
where the V and V signals have the same frequency.
s m

Due to more precision at higher frequencies, a balun transformer to implement the SPD may

be used instead of the shown ohmic resistances in the test set-up of Figure 10. The test

bridge configuration, with transversal impedance Z1 and longitudinal impedance Z2 does not

represent all conditions found in practice. Values and limits for the intended transmission

characteristics, such as frequency range and voltage, special considerations for terminating

impedances and measurement frequencies to be used are given in the relevant ITU-T

recommendations. An example of values and impedances for di
...

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