Terms and definitions of IEC 61643-11: LOW-VOLTAGE SURGE PROTECTIVE DEVICES （2/2）

IEC 61643-11: LOW-VOLTAGE SURGE PROTECTIVE DEVICES –

Part 11: Surge protective devices connected

to low-voltage power systems –

Requirements and test methods

Terms and definitions

3.1.30

type test

conformity test made on one or more items representative of the production

[IEC 60050-151:2001, 151-16-16]

3.1.31

routine test

test made on each SPD or on parts and materials as required to ensure that the product

meets the design specifications

[IEC 60050-151:2001, 151-16-17, modified]

3.1.32

acceptance tests

contractual test to prove to the customer that the item meets certain conditions of its

specification [IEC 60050-151:2001, 151-16-23]

3.1.33

decoupling network

an electrical circuit intended to prevent surge energy from being propagated to the power

network during energized testing of SPDs

NOTE This electrical circuit is sometimes called a "back filter".

3.1.34

Impulse test classification

3.1.34.1

class I tests

tests carried out with the impulse discharge current Iimp, with an 8/20 current impulse with a

crest value equal to the crest value of Iimp, and with a 1,2/50 voltage impulse

3.1.34.2

class II tests

tests carried out with the nominal discharge current In, and the 1,2/50 voltage impulse

3.1.34.3

class III tests

tests carried out with the 1,2/50 voltage - 8/20 current combination wave generator61643-11  IEC:2011

– 15 –

3.1.35

residual current device

RCD

switching device or associated devices intended to cause the opening of the power circuit

when the residual or unbalanced current attains a given value under specified conditions

3.1.36

sparkover voltage of a voltage-switching SPD

trigger voltage of a voltage-switching SPD

maximum voltage value at which the sudden change from high to low impedance starts for a voltage-switching SPD

3.1.37

specific energy for class I test

W/R

energy dissipated by a unit resistance of 1 Ώ with the impulse discharge current Iimp

NOTE This is equal to the time integral of the square of the current (W/R = ∫ i 2 d t).

3.1.38

prospective short-circuit current of a power supply

IP

current which would flow at a given location in a circuit if it were short-circuited at that

location by a link of negligible impedance

NOTE This prospective symmetrical current is expressed by its rms value.

3.1.39

follow current interrupt rating

Ifi

prospective short-circuit current that an SPD is able to interrupt without operation of a

disconnector

3.1.40

residual current

IPE

current flowing through the PE terminal of the SPD while energized at the reference test

voltage (UREF) when connected according to the manufacturer’s instructions

3.1.41

status indicator

device that indicates the operational status of an SPD, or a part of an SPD.

NOTE Such indicators may be local with visual and/or audible alarms and/or may have remote signalling and/or output contact capability.

3.1.42

output contact

contact included in a circuit separate from the main circuit of an SPD, and linked to a

disconnector or status indicator

3.1.43

multipole SPD

type of SPD with more than one mode of protection, or a combination of electrically

interconnected SPDs offered as a unit– 16 – 61643-11  IEC:2011

3.1.44

total discharge current

I Total

current which flows through the PE or PEN conductor of a multipole SPD during the total

discharge current test

NOTE 1 The aim is to take into account cumulative effects that occur when multiple modes of protection of a

multipole SPD conduct at the same time.

NOTE 2 I

Total is particularly relevant for SPDs tested according to test class I, and is used for the purpose of lightning protection equipotential bonding according to IEC 62305 series.

3.1.45

reference test voltage

U REF

r.m.s. value of voltage used for testing which depends on the mode of protection of the SPD,

the nominal system voltage, the system configuration and the voltage regulation within the

system

NOTE The reference test voltage is selected from Annex A based on the information given by the manufacturer according to 7.1.1 b8).

3.1.46

transition surge current rating for short-circuiting type SPD

Itrans

8/20 impulse current value exceeding the nominal discharge current In, that will cause a shortcircuiting type SPD to short-circuit

3.1.47

Voltage for clearance determination

U

max

highest measured voltage during surge applications according to 8.3.3 for clearance

determination

3.1.48

maximum discharge current  Imax

crest value of a current through the SPD having an 8/20 waveshape and magnitude according to the manufacturer's specification. Imax is equal to or greater than In