CLC/TR 50174-99-1:2015

SLOVENSKI STANDARD
01-junij-2015
Informacijska tehnologija - Polaganje kablov - 99-1. del: Daljinsko napajanje
Information technology - Cabling installation - Part 99-1: Remote powering
Ta slovenski standard je istoveten z: CLC/TR 50174-99-1:2015
ICS:
33.040.50 Vodi, zveze in tokokrogi Lines, connections and
circuits
35.110 Omreževanje Networking
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL REPORT
CLC/TR 50174-99-1
RAPPORT TECHNIQUE
TECHNISCHER BERICHT
April 2015
ICS 35.110
English Version
Information technology - Cabling installation - Part 99-1: Remote
powering
This Technical Report was approved by CENELEC on 2015-04-06.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2015 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. CLC/TR 50174-99-1:2015 E

Contents
Foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms, definitions, abbreviations and symbology . 6
3.1 Terms and definitions . 6
3.2 Abbreviations . 7
3.3 Symbology . 7
4 Overview . 7
4.1 General . 7
4.2 Published standards . 8
4.3 Recent developments . 9
4.4 Basic principles of remote powering . 10
4.5 Testing protocols and mathematical modelling . 10
5 Application of remote powering . 10
5.1 Channel length . 10
5.2 Cables of Category 5 (minimum) in EN 50173-1 . 11
5.3 Installation environment . 12
5.4 Cable bundles . 12
5.5 Connecting hardware of Category 5 (minimum) in EN 50173-1 . 13
5.6 Pathways and pathway systems . 13
6 Operation . 14
6.1 Design margin . 14
6.2 Cable bundle temperature and construction . 14
6.3 Range of temperature rises . 14
6.4 Installation guidance . 16
6.5 Record-keeping . 16
6.6 Cabling acceptance and trouble-shooting testing . 16
Annex A (informative) Powering concepts . 17
A.1 Principles . 17
A.2 Mathematical treatment . 17
A.3 Power dissipation . 19
Annex B (normative) Test protocol . 20
B.1 Background . 20
B.2 Test set-up . 20
B.3 Current delivery and measurement accuracy . 22
B.4 Test conditions . 22
B.5 Installation environment . 22
B.6 Data submission. 23

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Annex C (normative) Temperature rise modelling . 25
C.1 Model basics . 25
C.2 Power dissipated (P) . 25
C.3 Temperature difference from ambient temperature to bundle surface (∆T ) . 26
u
C.4 Temperature difference from bundle surface to bundle centre (∆T ) . 26
th
C.5 Temperature variation within the bundle (∆T(x)) . 27
C.6 Alternative presentation of the model . 27
Bibliography . 28

Foreword
This document (CLC/TR 50174-99-1:2015) has been prepared by CLC/TC 215
"Electrotechnical aspects of telecommunication equipment".
Attention is drawn to the possibility that some of the elements of this document may be the
subject of patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying
any or all such patent rights.

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Introduction
EN 50174 series specify the specification, planning and practices applicable to installation of
telecommunications cabling.
Balanced cabling in accordance with EN 50173-1 is increasingly used to provide power as well
as telecommunication services to a wide range of terminal equipment. This Technical Report
examines the effects of remote powering (i.e. thermal heating) on installed cabling.
The components considered are of those specified in EN 50173-1. The components of
Category 5 as defined in EN 50173:1995 were not specified in terms of current carrying
capacity etc.; they are not supported by this Technical Report.
This Technical Report supports recognized application standards for power feeding produced
by IEEE (IEEE 802.3at) but is not restricted to the current feeding specification of that
standard.
The delivery of POTS, ISDN, PoE and PoEplus using fully energized bundles of up to
100 cables in accordance with EN 50288-X-1 in ventilated pathways is not considered to
represent a problem and is not considered in this Technical Report. In addition, there is no
reported evidence of such installations of those remote powering applications producing
problems in unventilated conditions. As a result, this Technical Report will only consider such
situations if the modelling and subsequent testing of cabling implementations indicates any
cause for concern.
1 Scope
This Technical Report defines requirements and recommendations concerning limits for the
application and operation of remote powering using cabling comprising balanced cabling
components of Category 5 and above as defined in EN 50173-1.
This Technical Report also describes:
• a set of specific implementations which are the basis of a mathematical model for the
temperature increases in bundles of cables under remote powering conditions;
• a matching testing protocol used to provide data for the mathematical model;
NOTE The testing protocol was established in order to enable comparison of data from different sources in order
to support the development of the mathematical model and to develop appropriate planning and installation rules as
suggested by different installation conditions. It is not the role of CLC/TC 215 to develop test methods for balanced,
or other, cables and the protocol defined in Annex B is not as such a test method.
• the mathematical model that is employed as the basis for the resulting requirements and
recommendations.
Safety (electrical safety and protection, optical power, fire, etc.) and electromagnetic
compatibility (EMC) requirements are outside the scope of this Technical Report and are
covered by standards and regulations. However, information given in this Technical Report may
be of assistance in meeting these standards and regulations.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments)
applies.
EN 50173 series, Information technology – Generic cabling systems
EN 50173-1:2011, Information technology – Generic cabling systems – Part 1: General
requirements
EN 50174 series, Information technology – Cabling installation
EN 50174-2:2009 + A1:2011 + A2:2014, Information technology – Cabling installation – Part 2:
Installation planning and practices inside buildings
3 Terms, definitions, abbreviations and symbology
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 50173 series and in
EN 50174 series and the following apply.
3.1.1
requirement met by design
requirement that does not require testing and where conformance may be achieved either by
selection of appropriate components and their installation techniques or by conformance of a
related parameter
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3.1.2
remote powering
supply of electrical power to application specific equipment via balanced cabling
3.2 Abbreviations
For the purposes of this document, the abbreviations given in EN 50173 series and the
following apply.
d.c., DC direct current
U/UTP unscreened cable with unscreened balanced cable elements
F/UTP foil screened cable with unscreened balanced cable elements
S/FTP screened cable with foil screened balanced cable elements
3.3 Symbology
For the purposes of this document, the following symbols are used.
total temperature rise between the ambient temperature (or that of the
∆T
unpowered bundle) and the centre of the bundle
temperature rise between the outer surface and the centre of the bundle
∆T
th
temperature rise between the ambient temperature (or that of the unpowered
∆T
u
bundle) and the outer surface of the bundle
i the current per conductor (A)
c
n number of conductors per cable carrying remote powering current (i )
c c
N number of cables carrying remote powering current
R
average d.c. resistance per unit length (Ω/m) of conductors carrying remote
powering current
ρ constant relating to cable construction
th
ρ constant relating to installation environment
u
4 Overview
4.1 General
The principal concerns associated with the delivery of power are:
a) increases in the operating temperature of the cables (exceeding their specified
operating temperature);
b) damage to connecting hardware contacts where mating and de-mating occurs while the
power supply current is flowing;
c) the associated increase of channel attenuation/insertion loss, due to the increased
temperature of installed cables, which unless balanced by reduced installed lengths will
have a negative effect on channel ACR/PSACR (and may be associated with increased
system bit error rates).
This Technical Report demonstrates that the thermal impact of remote powering is proportional
to the number of cables in a bundle (and/or the number of bundles installed in a close proximity
to others) and the length over which that installation condition is maintained. Figure 1 is a
schematic of the distribution cabling subsystems defined by EN 50173-2 and EN 50173-6
(together with the supporting backbone cabling common to both standards).

BD FD
Fixed backbone cabling
EQP C C C C EQP
Distribution Backbone
No. of
cables in a bundle Cord Cord
or group of bundles
FD/SD TO/
Fixed distribution
...