IEC 60755:2017

General safety requirements for residual current operated protective devices

IEC 60775:2017(E) provides general minimum requirements, recommendations and information for the drafting of standards on residual current operated protective devices (hereinafter referred to as residual current devices, "RCDs"). It applies to any device providing residual current protection intended primarily for protection against electric shock hazard.
This first edition cancels and replaces IEC TR 60755 published in 2008 and constitutes a technical revision.
This edition includes the following significant technical changes with respect to IEC TR 60755:
a. restructuration of the document, as a Group Safety Publication, in compliance with Guide 104;
b. introduction of classification for type F RCDs;
c. introduction of Clause 9 for tests of RCDs (operating characteristics, electrical endurance, behaviour in short-circuit conditions, trip-free mechanism, test device, surges, reliability, EMC).
It has the status of a group safety publication in accordance with IEC Guide 104.

General Information

• Status: Published
• Publication Date: 25-Oct-2017
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 29.120.50 - Fuses and other overcurrent protection devices
• Technical Committee: SC 23E - Circuit-breakers and similar equipment for household use
• Drafting Committee: WG 2 - TC 23/SC 23E/WG 2
• Current Stage: PPUB - Publication issued
• Start Date: 17-Nov-2017
• Completion Date: 26-Oct-2017

Relations

• Replaces: IEC TR 60755:2008 - General requirements for residual current operated protective devices
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 60755 ®
Edition 1.0 2017-10
INTERNATIONAL
STANDARD
GROUP SAFETY PUBLICATION
General safety requirements for residual current operated protective devices
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IEC 60755 ®
Edition 1.0 2017-10
INTERNATIONAL
STANDARD
GROUP SAFETY PUBLICATION
General safety requirements for residual current operated protective devices

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.120.50 ISBN 978-2-8322-4935-2

– 2 – IEC 60755:2017 © IEC 2017

CONTENTS
FOREWORD . 7
INTRODUCTION . 9
1 Scope . 10
2 Normative references . 10
3 Terms and definitions . 11
4 Classification . 12
4.1 According to the method of operation . 12
4.2 According to the type of installation . 12
4.3 According to the possibility of adjusting the residual operating current . 12
4.4 According to their operating characteristics and behaviour in presence of DC
components . 12
4.5 According to time-delay (in presence of a residual current) . 12
4.6 According to the protection against external influences . 12
4.7 According to the method of mounting . 12
4.8 According to the method of connection . 13
4.9 According to the type of terminals . 13
4.10 According to the number of poles and current paths . 13
4.11 According to the instantaneous tripping current . 13
4.12 According to the I t characteristics . 14
4.13 According to overcurrent protection . 14
4.14 According to the method of construction . 14
4.15 According to the intended use . 14
4.16 According to the range of ambient air temperature . 15
5 Characteristics of residual current devices . 15
5.1 Summary of characteristics . 15
5.2 Rated quantities and other characteristics . 15
5.2.1 Rated voltages . 15
5.2.2 Rated current (I ) . 16
n
5.2.3 Rated frequency . 16
5.2.4 Rated making and breaking capacity (I ) . 16
m
5.2.5 Rated residual operating current (I ) . 16
Δn
5.2.6 Rated residual non-operating current (I ) . 16
Δno
5.2.7 Rated residual making and breaking capacity (I ) . 16
Δm
5.2.8 Rated conditional short-circuit current . 16
5.2.9 Rated conditional residual short-circuit current (I∆ ) . 16
c
5.2.10 Operating characteristics in case of residual currents with DC
components . 17
5.3 Standard and preferred values . 18
5.3.1 Values of rated operational voltage (U ) . 18
e
5.3.2 Values of rated current (I ) . 18
n
5.3.3 Standard values of rated residual operating current (I ) . 18
∆n
5.3.4 Standard value of residual non-operating current (I ) . 18
∆no
5.3.5 Preferred values of rated frequency . 18
5.3.6 Standard values of rated impulse withstand voltage (U ) . 18
imp
5.3.7 Standard values of operating time . 18

5.3.8 Standard minimum value of non-operating overcurrent in case of a load
through an RCD with two current paths . 19
5.3.9 Standard minimum value of non-operating overcurrent in case of a
single-phase load through a three- or four-pole or four-current-paths
RCD . 19
5.3.10 Minimum value of the rated making and breaking capacity (I ) . 19
m
5.3.11 Minimum value of the rated residual making and breaking capacity
(I∆ ) . 19
m
5.3.12 Preferred values of the rated conditional short-circuit current . 19
5.3.13 Preferred values of the rated conditional residual short-circuit current
(I∆ ) . 19
c
5.4 Coordination with short-circuit protective devices (SCPDs) . 19
6 Marking and other product information . 20
6.1 Information and marking for RCDs according to 4.15.1 . 20
6.2 Information and marking for RCDs according to 4.15.2 and 4.15.3 . 21
7 Conditions for operation in service and for installation . 22
7.1 Preferred ranges of application, reference values of influencing
quantities/factors and the associated test tolerances . 22
7.2 Conditions of installation . 22
7.3 Pollution degree . 22
7.4 Additional standard conditions for operation in service and for installation
when an RCD is incorporated or embedded in an equipment. 22
8 Requirements for construction and operation . 22
8.1 Mechanical design . 22
8.1.1 General . 22
8.1.2 Mechanism . 24
8.1.3 Clearance and creepage distances . 25
8.1.4 Screws, current-carrying parts and connections . 25
8.1.5 Terminals for external conductors . 26
8.2 Protection against electric shock . 26
8.3 Dielectric properties and isolating capability . 26
8.4 Temperature rise . 27
8.5 Operating characteristics . 27
8.5.1 General . 27
8.5.2 Operation in response to the type of residual current . 27
8.5.3 Operation in presence of a residual current equal to and greater than
I∆ . 28
n
8.5.4 Additional requirements for RCDs according to 4.15.2 and 4.15.3 . 29
8.6 Mechanical and electrical endurance . 29
8.7 Performance at short-circuit currents . 29
8.8 Resistance to mechanical shock and impact . 29
8.9 Resistance to heat . 29
8.10 Resistance to abnormal heat and to fire . 29
8.11 Test device . 30
8.12 Requirements for RCDs in case of loss of supply . 30
8.13 Behaviour of RCDs in case of overcurrent in the main circuit . 30
8.14 Behaviour of RCDs in case of current surges caused by impulse voltages . 30
8.15 Void . 30
8.16 Reliability . 30
8.17 Electromagnetic compatibility (EMC) . 31

– 4 – IEC 60755:2017 © IEC 2017
8.18 Resistance to temporary overvoltages (TOV) . 31
9 Preparation of test clauses for RCD product standards and of test clauses for
RCD incorporated or embedded in an equipment . 31
9.1 General . 31
9.1.1 General test conditions . 31
9.1.2 Additional test conditions for preparation of standards for RCDs
according to 4.15.2 .
...