Table of Contents

Introduction
1 Scope
2 Normative references
3 Definitions
3.1 surge protective device (SPD)
3.2 continuous operating current (I[c])
3.3 maximum continuous operating voltage (U[C])
3.4 voltage protection level (U[p])
3.5 measured limiting voltage
3.6 residual voltage (U[res])
3.7 temporary overvoltage (U[T])
3.8 temporary overvoltage of the network (U[TOV])
3.9 nominal discharge current (I[n])
3.10 impulse current (I[imp])
3.11 combination wave
3.12 8/20 current impulse
3.13 1.2/50 voltage impulse
3.14 thermal runaway
3.15 thermal stability
3.16 SPD disconnector
3.17 type tests
3.18 routine tests
3.19 acceptance tests
3.20 degrees of protection provided by enclosure (IP code)
3.21 voltage drop (in per cent) (delta U)
3.22 insertion loss
3.23 load-side surge withstand capability for a two prt SPD
3.24 short-circuit withstand
3.25 one-port SPD
3.26 two-port SPD
3.27 voltage switching type SPD
3.28 voltage limiting type SPD
3.29 combination type SPD
3.30 modes of protection
3.31 follow current (I[f])
3.32 maximum discharge current (I[max]) for class 2 test
3.33 degradation
3.34 residual current device (RCD)
3.35 nominal voltage of the system
3.36 impulse test classification
3.37 rated load current (I[L])
3.38 backup Overcurrent protection
3.39 maximum continuous operating voltage of the power
system at the SPD location (U[cs])
3.40 sparkover voltage of a voltage-switching SPD
3.41 lightning protection system (LPS)
4 Systems and equipment to be protected
4.1 Low-voltage power distribution systems
4.2 Characteristics of the equipment to be protected
5 Surge protective devices
5.1 Basic function of SPDs
5.2 Additional requirements
5.3 Classification of SPDs
5.4 Characteristics of SPDs
5.5 Additional information on characteristics of SPDs
6 Application of SPDs in low-voltage power distribution systems
6.1 Installation and its effect on the protection given by SPDs
6.2 Selection of SPD
6.3 Characteristics of auxiliary devices
7 Risk analysis
8 Co-ordination where equipment has both signaling and
power terminals
Annex A (informative) Typical information given with inquiries
and tenders and explanation of testing
procedures
Annex B (informative) Examples of relationship between U[c] and
the nominal voltage used in some systems
and example of relationship between U[p]
and U[c] for ZnO varistor
Annex C (informative) Environment 0 Surge voltages in LV systems
Annex D (informative) Partial lightning current calculations
Annex E (informative) TOV in the low voltage system due to
faults between high-voltage systems and earth
Annex F (informative) Co-ordination rules and principles
Annex G (informative) Examples of application
Annex H (informative) Examples of application of the risk analysis
Annex I (informative) System stresses
Annex J (informative) Criteria for selection of SPDs
Annex K (informative) Application of SPDs
Annex L (informative) Risk analysis
Related standards and bibliography
Figures
Tables

Abstract

Defines the principles for selection, operation, location and co-ordination of SPDs to be connected to 50 Hz to 60 Hz a.c. and to d.c. power circuits and equipment rated up to 1000 V r.m.s. or 1500 V d.c.

General Product Information

Published
Document Type	Standard
Status	Current
Publisher	Japanese Standards Association
Pages
ISBN
Supersedes	JIS C 5381-12:2004