ETSI EN 300 132-2 V2.5.1 (2016-10)

ETSI EN 300 132-2 V2.5.1 (2016-10)






EUROPEAN STANDARD
Environmental Engineering (EE);
Power supply interface at the input to
telecommunications and datacom (ICT) equipment;
Part 2: Operated by -48 V direct current (dc)

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2 ETSI EN 300 132-2 V2.5.1 (2016-10)



Reference
REN/EE-0252
Keywords
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 - NAF 742 C
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° 7803/88

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 only prevailing document is the
print of the Portable Document Format (PDF) version kept on a specific network drive within ETSI Secretariat.
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
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.

© European Telecommunications Standards Institute 2016.
All rights reserved.

TM TM TM
DECT , PLUGTESTS , UMTS and the ETSI logo are Trade Marks of ETSI registered for the benefit of its Members.
TM
3GPP and LTE™ are Trade Marks of ETSI registered for the benefit of its Members and
of the 3GPP Organizational Partners.
GSM® and the GSM logo are Trade Marks registered and owned by the GSM Association.
ETSI

---------------------- Page: 2 ----------------------
3 ETSI EN 300 132-2 V2.5.1 (2016-10)
Contents
Intellectual Property Rights . 5
Foreword . 5
Modal verbs terminology . 5
1 Scope . 6
2 References . 6
2.1 Normative references . 6
2.2 Informative references . 7
3 Definitions, symbols and abbreviations . 8
3.1 Definitions . 8
3.2 Symbols . 8
3.3 Abbreviations . 9
4 Requirements . 9
4.0 Interface "A". 9
4.1 Nominal voltage . 10
4.2 Normal service voltage range at interface "A" . 10
4.3 Abnormal service voltage range at interface "A" . 11
4.3.1 Abnormal service voltage range under steady state conditions . 11
4.3.2 Abnormal conditions: voltage variations, dips and short interruptions . 11
4.3.3 Voltage transients . 11
4.3.3.1 Voltage transient due to short-circuit and protective device clearance . 11
4.3.3.2 Short voltage transient due to switching and lightning . 12
4.3.4 Recovery from voltage transients . 12
4.4 Voltage changes due to the regulation of the power supply . 13
4.5 Power supply protection at interface "A" . 13
4.6 Maximum current drain . 13
4.7 Inrush Current on connection of interface "A" . 14
4.7.1 Limits . 14
4.7.2 Measurements . 15
4.8 Conducted immunity requirements of the telecommunications equipment at interface "A": narrowband
noise . 16
4.9 Conducted emissions requirements of the telecommunications and datacom (ICT) equipment at
interface "A" . 18
5 Earthing and bonding . 19
Annex A (informative): Identification of interface "A" . 20
Annex B (informative): -60 V systems . 21
DC
Annex C (informative): Guide for measuring inrush current and for transferring the
recorded pulses onto the limit chart . 22
C.1 Measurement . 22
C.2 Pulse waveform transfor mation . 22
C.3 Measurement of inrush current with filter capacitor current pulses . 25
Annex D (informative): Test arrangements for the injection of electrical noise at interface
"A" . 28
Annex E (informative): Wideband noise . 29
E.0 Wideband noise . 29
E.1 Emission of wideband noise . 29
E.1.1 Assessment of wideband noise . 29
ETSI

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4 ETSI EN 300 132-2 V2.5.1 (2016-10)
E.2 How to calculate wideband emission . 29
Annex F (informative): Protection dimensioning . 33
Annex G (informative): Effects of protective device operation transients in the power
distribution . 34
Annex H (informative): Bibliography . 35
History . 36

ETSI

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5 ETSI EN 300 132-2 V2.5.1 (2016-10)
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 (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.
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 telecommunications and datacom (ICT)
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 and datacom (ICT) equipment, as identified below:
Part 1: "Operated by alternating current (ac) derived from direct current (dc) sources";
Part 2: "Operated by -48 V 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 adoption of this EN: 5 October 2016
Date of latest announcement of this EN (doa): 31 January 2017
Date of latest publication of new National Standard
or endorsement of this EN (dop/e): 31 July 2017
Date of withdrawal of any conflicting National Standard (dow): 31 July 2017

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

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6 ETSI EN 300 132-2 V2.5.1 (2016-10)
1 Scope
The present document contains requirements and measurements methods for the physical interface that is situated
between the power supply system(s) and the power consuming telecommunications and datacom (ICT) equipment; this
point is called interface "A" as defined in clause 4.
The purpose of the present document is to use a power supply system with the same characteristics for all
telecommunications and datacom (ICT) equipment defined in the area of application:
- to facilitate inter working of different (types of) load units;
- to facilitate the standardization of telecommunications and datacom (ICT) equipment;
- to facilitate the installation, operation and maintenance in the same network of telecommunications and
datacom (ICT) equipment and systems from different origins.
The present document aims at providing electrical compatibility between the power supply equipment and the power
consuming telecommunications and datacom (ICT) equipment, and also between different system blocks connected to
the same power supply.
The requirements are defined for:
- the output of the power supply equipment or power supply installation of telecommunications centres
providing power at the interface "A";
- the power supply input of any type of telecommunications and datacom (ICT) equipment installed at
telecommunication centres that are connected to interface "A" powered by DC;
- any type of telecommunications and datacom (ICT) equipment, installed in access networks and
customers' premises, the DC interface "A" of which is also used by equipment requiring a supply to the present
document.
- any type of telecommunication and datacom (ICT) equipment powered by DC, used in the fixed and mobile
networks installed in different locations as building, shelter, street cabinet.
Disturbances on the power supply interface "A" relating to the continuous wave phenomena below 20 kHz are covered
within the present document.
The present document does not cover safety requirements, they are covered by relevant safety standards.
The present document does not cover EMC requirements, they are covered by relevant EMC standards.
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 B gives guidance on
working in conjunction with existing -60 V supply systems.
DC
NOTE 2: The DC voltage at interface "A" may be derived from the AC primary supply. The DC supply may
incorporate a backup battery
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/.
ETSI

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7 ETSI EN 300 132-2 V2.5.1 (2016-10)
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 necessary for the application of the present document.
[1] CENELEC EN 60269-1: "Low-voltage fuses - Part 1: General requirements".
[2] CENELEC EN 60934: "Circuit-breakers for equipment (CBE)".
[3] Void.
[4] Void.
[5] CENELEC EN 61000-4-5: "Electromagnetic compatibility (EMC) - Part 4-5: Testing and
measurement techniques - Surge immunity test".
[6] Void.
[7] CENELEC EN 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".
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] Recommendation ITU-T Q.551: "Transmission characteristics of digital exchanges".
[i.2] Recommendation ITU-T Q.552: "Transmission characteristics at 2-wire analogue interfaces of
digital exchanges".
[i.3] Recommendation ITU-T Q.553: "Transmission characteristics at 4-wire analogue interfaces of
digital exchanges".
[i.4] Recommendation ITU-T Q.554: "Transmission characteristics at digital interfaces of digital
exchanges".
[i.5] ETSI TR 100 283: "Environmental Engineering (EE); Transient voltages at Interface "A" on
telecommunications direct current (dc) power distributions".
[i.6] US Department of Defence MIL-STD-461E: "Requirements for the control of electromagnetic
interference characteristics of subsystems and equipment".
[i.7] ETSI EN 300 253: "Environmental Engineering (EE); Earthing and bonding of ICT equipment
powered by -48 VDC in telecom and data centres".
[i.8] Recommendation ITU-T O.41: "Psophometer for use on telephone-type circuits".
[i.9] IEC 60050-601: "International Electrotechnical Vocabulary. Chapter 601: Generation,
transmission and distribution of electricity - General" (Area 826 "Electrical installations",
section 826-11 "Voltages and currents").
ETSI

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8 ETSI EN 300 132-2 V2.5.1 (2016-10)
3 Definitions, symbols and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
abnormal service 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
fully equipped equipment: configuration that corresponds to the maximum power consumption measured at -48 V
DC
with the equipment in operating conditions (e.g. not in standby mode)
NOTE: When there are several fully equipped configurations because of different combinations of possible
boards, the configuration with the boards that gives the highest power consumption should be considered.
interface "A": terminals at which the power supply is connected to the system block
NOTE 1: See also figure 1 and annex A.
NOTE 2: This is a functional definition and not an exact depiction of the physical location.
malfunction: termination of the normal service
maximum steady state input current (I ): maximum steady state input current, stated by the manufacturer, for a
m
fully equipped equipment under test connected to interface "A" at nominal voltage
nominal voltage: value of the voltage by which the electrical installation or part of the electrical installation is
designated and identified [i.9]
normal operating voltage range: voltage range at interface "A" where the system operates most of the time, e.g. in
general linked to battery floating voltage
normal service: service mode where telecommunications and datacom (ICT) equipment operates within its
specification which includes a defined restart time after malfunction or full interruption
normal service voltage range: range of steady-state voltages over which the equipment will maintain normal service
operating voltage: value of the voltage under normal conditions, at a given instant and a given point of the system [i.9]
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 A.
telecommunication centre: location where telecommunications and datacom (ICT) equipment is installed and which is
the sole responsibility of the operator
telecommunications and datacom equipment: Information and Communication Technology (ICT) equipment
3.2 Symbols
For the purposes of the present document, the following symbols apply:
I instantaneous inrush current
t
I maximum steady state input current
m
L inductance of inductive element of LISN
R resistance of resistive element of LISN
ETSI

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9 ETSI EN 300 132-2 V2.5.1 (2016-10)
t time
Z capacitive impedance of immunity measurement circuit
c
Z resistive impedance of immunity measurement circuit
m
μs microsecond
3.3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
AC Alternating Current
DC Direct Current
NOTE: Also when used as a suffix to units of measurement.
EMC ElectroMagnetic Compatibility
ESR Equivalent Series Resistance
EUT Equipment Under Test
HOD High-Ohmic Distributions
ICT Information and Communication Technology
LISN Line Impedance Stabilization Network
LOD Low-Ohmic Distributions
RF Radio Frequency
rms root mean square
TR Technical Report
V Voltage Direct Current
DC
NOTE: Also when used as a suffix to units of measurement.
4 Requirements
4.0 Interface "A"
The power supply interface, interface "A" of figure 1, is a physical point to which all the requirements are related.
This point is situated between the power supply system(s) and the power consuming telecommunications and datacom
(ICT) equipment.
An example of a configuration in which interface "A" is identified is given in annex A.
ETSI

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10 ETSI EN 300 132-2 V2.5.1 (2016-10)

Figure 1: Identification of interface "A"
4.1 Nominal voltage
The interface and equipment shall be designated and identified by a nominal voltage.
The nominal voltage at interface "A" shall be -48 V (positive conductor is connected to earth as defined in ETSI
DC
EN 300 253 [i.7]).
NOTE: In most cases the nominal voltage of interface "A" is based on a 24 cell lead-acid battery.
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
There shall be no degradation of service performance when telecommunication and datacom (ICT) equipment is
operating at voltages within the normal service voltage range.
This requirement shall be verified by applying the following tests at interface "A". The testing and measurement
techniques are described in CENELEC EN 61000-4-29 [7].
Table 1
Test level of Normal Duration Basic standard Rise and fall time of Performance criteria
service voltage variation voltage change
From -40,5 V to -57,0 V 0,1 s CENELEC Between 1 μs and 50 μs on No degradation in the
EN 61000-4-29 [7] service performance
From -57,0 V to -40,5 V 0,1 s 100 Ω resistive load
(see basic standard for test during and after the
test
generator)

In the case of telecommunication and datacom (ICT) equipment with power supply input redundancies (e.g. power
supply 1"PS1" and power supply 2 "PS2"), this test shall be performed at each power supply input at a time with and
without the second power supply.
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.
ETSI

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11 ETSI EN 300 132-2 V2.5.1 (2016-10)
NOTE 3: The operator can ask the manufacturer of telecommunications and datacom (ICT) equipment for any test
made at nominal voltage -48 V to be repeated at the most common operating voltage within the normal
operating voltage range e.g. -54,5 V for power consumption test.
4.3 Abnormal service voltage range at interface "A"
4.3.1 Abnormal service voltage range under steady state conditions
Telecommunications equipment operated at -48 V shall not suffer any damage when subjected to the following
DC
voltage ranges:
Table 2
0,0 V to -40,5 V and
DC DC
-57,0 V to -60,0 V
DC DC

Following the restoration of the supply to the normal voltage range, the power conversion and management systems on
the load side of interface "A" shall automatically restore normal service. The telecommunications and datacom (ICT)
equipment shall then resume operation according to its specifications. The abnormal service voltage shall not lead to the
disconnection of the power supply e.g. by causing circuit breakers, fuses or other such devices to operate.
NOTE: It is acceptable that the system may restart when the voltage is -40,5 V or greater within the nominal service
voltage range and/or after a time delay.
4.3.2 Abnormal conditions: voltage variations, dips and short interruptions
Telecommunication equipment shall not suffer any damage when subject to the following abnormal voltage range that
can be present at the interface "A".
Table 3
Voltage variation Duration Basic standard Rise and fall time of Performance criteria
voltage change
From -40,5 V to -60,0 V 0,1 s CENELEC Self restart to a
Between 1 μs and
and from -60 V to -40,5 EN 61000-4-29 [7] normal service of the
50 μs on 100 Ω
V equipment without
resistive load (see
From -57,0 V to 0,0 V 0,1 s operator intervention
basic standard)
after the test
and from 0,0 V to -57,0 V

In the case of telecommunication and datacom (ICT) equipment with power supply input redundancies (e.g. power
supply (A) and power supply B), this test shall be performed at each power supply input at a time with and without the
second power supply.
4.3.3 Voltage transients
4.3.3.1 Voltage transient due to short-circuit and protective device clearance
Voltage transients may occur at interface "A" when faults (e.g. short circuits) occur in the power distribution system.
These transients are characterized by a voltage drop in the range: 0 V to -40,5 V , followed by an overvoltage often
DC DC
in excess of the maximum steady state abnormal service voltage range and dependent upon the power distribution up to
interface "A" and the equipment connected to interface "A".
NOTE 1: ETSI TR 100 283 [i.5] provides guidance for the protection of telecommunications equipment from the
transients.
ETSI

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12 ETSI EN 300 132-2 V2.5.1 (2016-10)
NOTE 2: A protective device operation transient results from a low impedance fault to ground on the equipment
side of a protective device (fuse or circuit breaker) connected to a power distribution bus. In the power
bus, then voltage is reduced (undervoltage) due to high current flowing to ground through the protective
device and the short ground. When the protective device opens, the release energy stored in the
inductance of the bus causes an initial high voltage overshoot of short duration, followed by a longer
interval voltage overshoot that decays toward the steady state bus voltage. The undervoltage portion of
the protective device operation transient, may cause a voltage drop at the input terminals of the other
equipment connected to the common power bus that may affects the functionality of the equipment itself.
The propagation of the protective device operation transient on the power bus depends by the type of
power distribution system and can be minimized by:
Isolating the fault using High-Ohmic Distributions (HOD) or Low-Ohmic Distributions (LOD); see
annex G, or
Using redundant powering systems (i.e. dual feeders (A+B) from two separate power sources
(A+B)). Equipment having two power feeds is fitted with OR-ing devices or separate power supply
units; or
Using large storage capacitance to provide a holdup time equal to or larger than the protective
device operating time.
4.3.3.2 Short voltage transient due to switching and lightning
The surge immunity performance of telecommunications and datacom (ICT) equipment against abnormal overvoltage
shall be verified using the test procedure described below and the combination wave generator defined in the standard
CENELEC EN 61000-4-5 [5]. This generator can produce the pulse shape of 1,2 μs-rise time/50 μs-duration in open
circuit and 8 μs-rise time/20 μs-duration in short circuit.
Tests with positive of power supply connected to ground shall be performed with the operating input voltage of -54 V
accordingly with the following test specification.
Table 4
Tran
...

Draft ETSI EN 300 132-2 V2.4.16 (2016-06)






EUROPEAN STANDARD
Environmental Engineering (EE);
Power supply interface at the input to
telecommunications and datacom (ICT) equipment;
Part 2: Operated by -48 V direct current (dc)

---------------------- Page: 1 ----------------------
2 Draft ETSI EN 300 132-2 V2.4.16 (2016-06)



Reference
REN/EE-0252
Keywords
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 - NAF 742 C
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° 7803/88

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 only prevailing document is the
print of the Portable Document Format (PDF) version kept on a specific network drive within ETSI Secretariat.
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
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.

© European Telecommunications Standards Institute 2016.
All rights reserved.

TM TM TM
DECT , PLUGTESTS , UMTS and the ETSI logo are Trade Marks of ETSI registered for the benefit of its Members.
TM
3GPP and LTE™ are Trade Marks of ETSI registered for the benefit of its Members and
of the 3GPP Organizational Partners.
GSM® and the GSM logo are Trade Marks registered and owned by the GSM Association.
ETSI

---------------------- Page: 2 ----------------------
3 Draft ETSI EN 300 132-2 V2.4.16 (2016-06)
Contents
Intellectual Property Rights . 5
Foreword . 5
Modal verbs terminology . 5
1 Scope . 6
2 References . 6
2.1 Normative references . 6
2.2 Informative references . 7
3 Definitions, symbols and abbreviations . 8
3.1 Definitions . 8
3.2 Symbols . 8
3.3 Abbreviations . 9
4 Requirements . 9
4.0 Interface "A". 9
4.1 Nominal voltage . 10
4.2 Normal service voltage range at interface "A" . 10
4.3 Abnormal service voltage range at interface "A" . 11
4.3.1 Abnormal service voltage range under steady state conditions . 11
4.3.2 Abnormal conditions: voltage variations, dips and short interruptions . 11
4.3.3 Voltage transients . 11
4.3.3.1 Voltage transient due to short-circuit and protective device clearance . 11
4.3.3.2 Short voltage transient due to switching and lightning . 12
4.3.4 Recovery from voltage transients . 12
4.4 Voltage changes due to the regulation of the power supply . 13
4.5 Power supply protection at interface "A" . 13
4.6 Maximum current drain . 13
4.7 Inrush Current on connection of interface "A" . 14
4.7.1 Limits . 14
4.7.2 Measurements . 15
4.8 Conducted immunity requirements of the telecommunications equipment at interface "A": narrowband
noise . 16
4.9 Conducted emissions requirements of the telecommunications and datacom (ICT) equipment at
interface "A" . 18
5 Earthing and bonding . 19
Annex A (informative): Identification of interface "A" . 20
Annex B (informative): -60 V systems . 21
DC
Annex C (informative): Guide for measuring inrush current and for transferring the
recorded pulses onto the limit chart . 22
C.1 Measurement . 22
C.2 Pulse waveform transfor mation . 22
C.3 Measurement of inrush current with filter capacitor current pulses . 25
Annex D (informative): Test arrangements for the injection of electrical noise at interface
"A" . 28
Annex E (informative): Wideband noise . 29
E.0 Wideband noise . 29
E.1 Emission of wideband noise . 29
E.1.1 Assessment of wideband noise . 29
ETSI

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4 Draft ETSI EN 300 132-2 V2.4.16 (2016-06)
E.2 How to calculate wideband emission . 29
Annex F (informative): Protection dimensioning . 33
Annex G (informative): Effects of protective device operation transients in the power
distribution . 34
Annex H (informative): Bibliography . 35
History . 36

ETSI

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5 Draft ETSI EN 300 132-2 V2.4.16 (2016-06)
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 (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.
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 telecommunications and datacom (ICT)
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 and datacom (ICT) equipment, as identified below:
Part 1: "Operated by alternating current (ac) derived from direct current (dc) sources";
Part 2: "Operated by -48 V direct current (dc)";
Part 3-0: "Operated by rectified current source, alternating current source or direct current source up to 400 V".

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

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.
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6 Draft ETSI EN 300 132-2 V2.4.16 (2016-06)
1 Scope
The present document contains requirements and measurements methods for the physical interface that is situated
between the power supply system(s) and the power consuming telecommunications and datacom (ICT) equipment; this
point is called interface "A" as defined in clause 4.
The purpose of the present document is to use a power supply system with the same characteristics for all
telecommunications and datacom (ICT) equipment defined in the area of application:
- to facilitate inter working of different (types of) load units;
- to facilitate the standardization of telecommunications and datacom (ICT) equipment;
- to facilitate the installation, operation and maintenance in the same network of telecommunications and
datacom (ICT) equipment and systems from different origins.
The present document aims at providing electrical compatibility between the power supply equipment and the power
consuming telecommunications and datacom (ICT) equipment, and also between different system blocks connected to
the same power supply.
The requirements are defined for:
- the output of the power supply equipment or power supply installation of telecommunications centres
providing power at the interface "A";
- the power supply input of any type of telecommunications and datacom (ICT) equipment installed at
telecommunication centres that are connected to interface "A" powered by DC;
- any type of telecommunications and datacom (ICT) equipment, installed in access networks and
customers' premises, the DC interface "A" of which is also used by equipment requiring a supply to the present
document.
- any type of telecommunication and datacom (ICT) equipment powered by DC, used in the fixed and mobile
networks installed in different locations as building, shelter, street cabinet.
Disturbances on the power supply interface "A" relating to the continuous wave phenomena below 20 kHz are covered
within the present document.
The present document does not cover safety requirements, they are covered by relevant safety standards.
The present document does not cover EMC requirements, they are covered by relevant EMC standards.
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 B gives guidance on
working in conjunction with existing -60 V supply systems.
DC
NOTE 2: The DC voltage at interface "A" may be derived from the AC primary supply. The DC supply may
incorporate a backup battery
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/.
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7 Draft ETSI EN 300 132-2 V2.4.16 (2016-06)
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 necessary for the application of the present document.
[1] CENELEC EN 60269-1: "Low-voltage fuses - Part 1: General requirements".
[2] CENELEC EN 60934: "Circuit-breakers for equipment (CBE)".
[3] Void.
[4] Void.
[5] CENELEC EN 61000-4-5: "Electromagnetic compatibility (EMC) - Part 4-5: Testing and
measurement techniques - Surge immunity test".
[6] Void.
[7] CENELEC EN 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".
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] Recommendation ITU-T Q.551: "Transmission characteristics of digital exchanges".
[i.2] Recommendation ITU-T Q.552: "Transmission characteristics at 2-wire analogue interfaces of
digital exchanges".
[i.3] Recommendation ITU-T Q.553: "Transmission characteristics at 4-wire analogue interfaces of
digital exchanges".
[i.4] Recommendation ITU-T Q.554: "Transmission characteristics at digital interfaces of digital
exchanges".
[i.5] ETSI TR 100 283: "Environmental Engineering (EE); Transient voltages at Interface "A" on
telecommunications direct current (dc) power distributions".
[i.6] US Department of Defence MIL-STD-461E: "Requirements for the control of electromagnetic
interference characteristics of subsystems and equipment".
[i.7] ETSI EN 300 253: "Environmental Engineering (EE); Earthing and bonding of ICT equipment
powered by -48 VDC in telecom and data centres".
[i.8] Recommendation ITU-T O.41: "Psophometer for use on telephone-type circuits".
[i.9] IEC 60050-601: "International Electrotechnical Vocabulary. Chapter 601: Generation,
transmission and distribution of electricity - General" (Area 826 "Electrical installations",
section 826-11 "Voltages and currents").
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8 Draft ETSI EN 300 132-2 V2.4.16 (2016-06)
3 Definitions, symbols and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
abnormal service 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
fully equipped equipment: configuration that corresponds to the maximum power consumption measured at -48 V
DC
with the equipment in operating conditions (e.g. not in standby mode)
NOTE: When there are several fully equipped configurations because of different combinations of possible
boards, the configuration with the boards that gives the highest power consumption should be considered.
interface "A": terminals at which the power supply is connected to the system block
NOTE 1: See also figure 1 and annex A.
NOTE 2: This is a functional definition and not an exact depiction of the physical location.
malfunction: termination of the normal service
maximum steady state input current (I ): maximum steady state input current, stated by the manufacturer, for a
m
fully equipped equipment under test connected to interface "A" at nominal voltage
nominal voltage: value of the voltage by which the electrical installation or part of the electrical installation is
designated and identified [i.9]
normal operating voltage range: voltage range at interface "A" where the system operates most of the time, e.g. in
general linked to battery floating voltage
normal service: service mode where telecommunications and datacom (ICT) equipment operates within its
specification which includes a defined restart time after malfunction or full interruption
normal service voltage range: range of steady-state voltages over which the equipment will maintain normal service
operating voltage: value of the voltage under normal conditions, at a given instant and a given point of the system [i.9]
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 A.
telecommunication centre: location where telecommunications and datacom (ICT) equipment is installed and which is
the sole responsibility of the operator
telecommunications and datacom equipment: Information and Communication Technology (ICT) equipment
3.2 Symbols
For the purposes of the present document, the following symbols apply:
I instantaneous inrush current
t
I maximum steady state input current
m
L inductance of inductive element of LISN
R resistance of resistive element of LISN
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9 Draft ETSI EN 300 132-2 V2.4.16 (2016-06)
t time
Z capacitive impedance of immunity measurement circuit
c
Z resistive impedance of immunity measurement circuit
m
μs microsecond
3.3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
AC Alternating Current
DC Direct Current
NOTE: Also when used as a suffix to units of measurement.
EMC ElectroMagnetic Compatibility
ESR Equivalent Series Resistance
EUT Equipment Under Test
HOD High-Ohmic Distributions
ICT Information and Communication Technology
LISN Line Impedance Stabilization Network
LOD Low-Ohmic Distributions
RF Radio Frequency
rms root mean square
TR Technical Report
V Voltage Direct Current
DC
NOTE: Also when used as a suffix to units of measurement.
4 Requirements
4.0 Interface "A"
The power supply interface, interface "A" of figure 1, is a physical point to which all the requirements are related.
This point is situated between the power supply system(s) and the power consuming telecommunications and datacom
(ICT) equipment.
An example of a configuration in which interface "A" is identified is given in annex A.
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10 Draft ETSI EN 300 132-2 V2.4.16 (2016-06)

Figure 1: Identification of interface "A"
4.1 Nominal voltage
The interface and equipment shall be designated and identified by a nominal voltage.
The nominal voltage at interface "A" shall be -48 V (positive conductor is connected to earth as defined in ETSI
DC
EN 300 253 [i.7]).
NOTE: In most cases the nominal voltage of interface "A" is based on a 24 cell lead-acid battery.
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
There shall be no degradation of service performance when telecommunication and datacom (ICT) equipment is
operating at voltages within the normal service voltage range.
This requirement shall be verified by applying the following tests at interface "A". The testing and measurement
techniques are described in CENELEC EN 61000-4-29 [7].
Table 1
Test level of Normal Duration Basic standard Rise and fall time of Performance criteria
service voltage variation voltage change
From -40,5 V to -57,0 V 0,1 s CENELEC Between 1 μs and 50 μs on No degradation in the
EN 61000-4-29 [7] service performance
From -57,0 V to -40,5 V 0,1 s 100 Ω resistive load
(see basic standard for test during and after the
test
generator)

In the case of telecommunication and datacom (ICT) equipment with power supply input redundancies (e.g. power
supply 1"PS1" and power supply 2 "PS2"), this test shall be performed at each power supply input at a time with and
without the second power supply.
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.
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11 Draft ETSI EN 300 132-2 V2.4.16 (2016-06)
NOTE 3: The operator can ask the manufacturer of telecommunications and datacom (ICT) equipment for any test
made at nominal voltage -48 V to be repeated at the most common operating voltage within the normal
operating voltage range e.g. -54,5 V for power consumption test.
4.3 Abnormal service voltage range at interface "A"
4.3.1 Abnormal service voltage range under steady state conditions
Telecommunications equipment operated at -48 V shall not suffer any damage when subjected to the following
DC
voltage ranges:
Table 2
0,0 V to -40,5 V and
DC DC
-57,0 V to -60,0 V
DC DC

Following the restoration of the supply to the normal voltage range, the power conversion and management systems on
the load side of interface "A" shall automatically restore normal service. The telecommunications and datacom (ICT)
equipment shall then resume operation according to its specifications. The abnormal service voltage shall not lead to the
disconnection of the power supply e.g. by causing circuit breakers, fuses or other such devices to operate.
NOTE: It is acceptable that the system may restart when the voltage is -40,5 V or greater within the nominal service
voltage range and/or after a time delay.
4.3.2 Abnormal conditions: voltage variations, dips and short interruptions
Telecommunication equipment shall not suffer any damage when subject to the following abnormal voltage range that
can be present at the interface "A".
Table 3
Voltage variation Duration Basic standard Rise and fall time of Performance criteria
voltage change
From -40,5 V to -60,0 V 0,1 s CENELEC Self restart to a
Between 1 μs and
and from -60 V to -40,5 EN 61000-4-29 [7] normal service of the
50 μs on 100 Ω
V equipment without
resistive load (see
From -57,0 V to 0,0 V 0,1 s operator intervention
basic standard)
after the test
and from 0,0 V to -57,0 V

In the case of telecommunication and datacom (ICT) equipment with power supply input redundancies (e.g. power
supply (A) and power supply B), this test shall be performed at each power supply input at a time with and without the
second power supply.
4.3.3 Voltage transients
4.3.3.1 Voltage transient due to short-circuit and protective device clearance
Voltage transients may occur at interface "A" when faults (e.g. short circuits) occur in the power distribution system.
These transients are characterized by a voltage drop in the range: 0 V to -40,5 V , followed by an overvoltage often
DC DC
in excess of the maximum steady state abnormal service voltage range and dependent upon the power distribution up to
interface "A" and the equipment connected to interface "A".
NOTE 1: ETSI TR 100 283 [i.5] provides guidance for the protection of telecommunications equipment from the
transients.
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NOTE 2: A protective device operation transient results from a low impedance fault to ground on the equipment
side of a protective device (fuse or circuit breaker) connected to a power distribution bus. In the power
bus, then voltage is reduced (undervoltage) due to high current flowing to ground through the protective
device and the short ground. When the protective device opens, the release energy stored in the
inductance of the bus causes an initial high voltage overshoot of short duration, followed by a longer
interval voltage overshoot that decays toward the steady state bus voltage. The undervoltage portion of
the protective device operation transient, may cause a voltage drop at the input terminals of the other
equipment connected to the common power bus that may affects the functionality of the equipment itself.
The propagation of the protective device operation transient on the power bus depends by the type of
power distribution system and can be minimized by:
Isolating the fault using High-Ohmic Distributions (HOD) or Low-Ohmic Distributions (LOD); see
annex G, or
Using redundant powering systems (i.e. dual feeders (A+B) from two separate power sources
(A+B)). Equipment having two power feeds is fitted with OR-ing devices or separate power supply
units; or
Using large storage capacitance to provide a holdup time equal to or larger than the protective
device operating time.
4.3.3.2 Short voltage transient due to switching and lightning
The surge immunity performance of telecommunications and datacom (ICT) equipment against abnormal overvoltage
shall be verified using the test procedure described below and the combination wave generator defined in the standard
CENELEC EN 61000-4-5 [5]. This generator can produce the pulse shape of 1,2 μs-rise time/50 μs-duration in open
circuit and 8 μs-rise time/20 μs-duration in s
...