IEC TR 63139:2018

IEC TR 63139 ®
Edition 1.0 2018-10
TECHNICAL
REPORT
colour
inside
Explanation of the mathematical addition of working voltages, insulation
between circuits and use of PELV in TC 34 standards

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IEC TR 63139 ®
Edition 1.0 2018-10
TECHNICAL
REPORT
colour
inside
Explanation of the mathematical addition of working voltages, insulation

between circuits and use of PELV in TC 34 standards

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ISBN 978-2-8322-6163-7
ICS 29.140.01
– 2 – IEC TR 63139:2018 © IEC 2018
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Mathematical addition of working voltages . 6
5 Insulation between circuits. 9
5.1 General . 9
5.2 Insulation requirements between active parts and accessible conductive
parts . 9
5.3 Possible failure conditions . 11
6 Circuits analysis . 13
7 Use of PELV . 15
7.1 General . 15
7.2 Characteristics of PELV (protective extra low voltage) circuits . 16
7.3 Requirements for PELV circuits in addition to SELV . 16
7.3.1 Voltage limitations . 16
7.3.2 Touch current and protective conductor current . 17
7.4 Summary of the proposed changes to IEC 60598-1 and IEC 61347-1 . 18
8 Insulation between LV supply and control line conductors . 18
Bibliography . 20

Figure 1 – Input/output failure simulation . 8
Figure 2 – Examples of controlgear with different insulation systems . 11
Figure 3 – Condition A: failure between input and output circuits . 11
Figure 4 – Condition B: earth failure/equipotential bonding failure (interruption of the
connection continuity) . 12
Figure 5 – Condition C: insulation failure between output circuits and accessible
earthed metal part. 12
Figure 6 – Condition D: insulation failure between output circuit to conductive parts
which are connected together (equipotential bonding) . 12
Figure 7 – Condition E: insulation failure between output circuit and different
conductive parts not connected together (no equipotential bonding) . 13
Figure 8 – PELV circuit in the most adverse condition (touch voltage is the sum of U
E
and U ). 17
Figure 9 – PELV circuit with a person located in an equipotential location (touch
voltage is U only) . 17
Table 1 – Addition of voltages . 8
Table 2 – Insulation requirements between active parts and accessible conductive
parts . 10
Table 3 – Circuit analysis overview . 13

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
EXPLANATION OF THE MATHEMATICAL ADDITION
OF WORKING VOLTAGES, INSULATION BETWEEN CIRCUITS
AND USE OF PELV IN TC 34 STANDARDS

FOREWORD
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The main task of IEC technical committees is to prepare International Standards. However, a
technical committee may propose the publication of a Technical Report when it has collected
data of a different kind from that which is normally published as an International Standard, for
example "state of the art".
IEC TR 63139, which is a Technical Report, has been prepared by IEC technical committee
34: Lamps and related equipment.
The text of this Technical Report is based on the following documents:
DTR Report on voting
34/415/DTR 34/493A/RVDTR
Full information on the voting for the approval of this Technical Report can be found in the
report on voting indicated in the above table.

– 4 – IEC TR 63139:2018 © IEC 2018
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INTRODUCTION
This document provides background information to the following subjects being introduced
into IEC TC 34 standards to cover new technologies associated with the use of LED light
sources and controllable products.
This document consists of the following subdivisions:
Clause 4 – Mathematical addition of working voltages;
Clause 5 – Insulation between circuits;
Clause 6 – Use of protective extra low voltage (PELV);
Clause 7 – Insulation between LV supply and control line conductors.

– 6 – IEC TR 63139:2018 © IEC 2018
EXPLANATION OF THE MATHEMATICAL ADDITION
OF WORKING VOLTAGES, INSULATION BETWEEN CIRCUITS
AND USE OF PELV IN TC 34 STANDARDS

1 Scope
This document is related to the insulation coordination in TC 34 standards and provides
explanations on mathematical addition of working voltages, insulation between circuits, use of
protective extra low voltage (PELV) and insulation between LV supply and control line
conductors in order to cover new technologies associated with the use of LED light sources
and controllable products.
It describes in which way the addition of supply voltages and working voltages can be
arranged for an assessment of the electrical insulation requirements (e.g. creepage distances
and clearances) in a system if a first failure occurs.
Furthermore the actual failure scenarios given in IEC 60598-1:2014 and
...