IEC 60132-1:1962

SLOVENSKI STANDARD
01-avgust-1995
Electrical relays - Part 13: Biased (percentage) differential relays
Electrical relays - Part 13: Biased (percentage) differential relays
Relais électriques - Treizième partie: Relais différentiels à pourcentage
Ta slovenski standard je istoveten z: IEC 60255-13
ICS:
29.120.70 Releji Relays
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

NORME
CEI
INTERNATIONALE IEC
255-13
INTERNATIONAL
Première édition
STANDARD
First edition
Relais électriques
Treizième partie:
Relais différentiels à pourcentage
Electrical relays
Part 13:
Biased (percentage)
differential relays
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— 3 —
CONTENTS
Page
FOREWORD 5
PREFACE
SECTION ONE — SCOPE AND DEFINITIONS
Clause
1. Scope 7
2. Definitions 7
SECTION Two — REQUIREMENTS
3. Standard values 9
4. Operation and accuracy
5. Methods of presenting relay characteristics and performance
6. Thermal requirements
7. Mechanical requirements
8. Values of the limits of the operative range of the auxiliary energizing quantities
9. Shock and vibration
10. Contact performance
11. Rated burden 17
12. Insulation 17
13. Markings and data 17
14. High-frequency disturbance test 17
SECTION THREE — TEST METHODS
15. Tests related to accuracy and operating characteristics
16. Tests for thermal requirements
17. Tests of performance with through current 21
18. Tests for mechanical requirements 21

INTERNATIONAL ELECTROTECHNICAL COMMISSION
ELECTRICAL RELAYS
Part 13: Biased (percentage) differential relays
FOREWORD
The formal decisions or agreements of the IEC on technical matters, prepared by Technical Committees on which all the
1)
National Committees having a special interest therein are represented, express, as nearly as possible. an international
consensus of opinion on the subjects dealt with.
They have the form of recommendations for international use and they are accepted by the National Committees in that
2)
sense.
In order to promote international unification, the IEC expresses the wish that all National Committees should adopt the
3)
text of the I EC recommendation for their national rules in so far as national conditions will permit. Any divergence
between the IEC recommendation and the corresponding national rules should, as far as possible, be clearly indicated in
the latter.
PREFACE
This standard has been prepared by Sub-Committee 41B: Measuring Relays, of IEC Technical Committee No. 41:
Electrical Relays.
Drafts were discussed at the meetings held Nice in 1976 and in Milan in 1977. A draft, Document 4lB(Central Office)13,
was submitted to the National Committees for approval under the Six Months' Rule in October 1978.
The National Committees of the following countries voted explicitly in favour of publication:
Korea (Democratic People's Republic of)
Australia
Norway
Austria
Poland
Belgium
Romania
Denmark
South Africa (Republic of)
France
Germany Sweden
Switzerland
Italy
Turkey
Japan
Korea (Republic of) United Kingdom
United States of America
Technical Committee No. 41 has decided to classify its future publications on a hierarchical basis as follows:
General standards;
First level:
Second level: Generic standards relating wholly or partly to a family of relays;
Third level: Standards applicable wholly or partly to a particular group of relays;
Fourth level: Particular requirements or specifications relating to a specific type (or pattern) of relay.
This standard, applicable .to a particular group of measuring relays with more than one input energizing quantity, is
hierarchically a third-level document.
Other IEC publications quoted in this standard:
Publications Nos. 255-0-20: Electrical Relays—Contact Performance of Electrical Relays.
Part 5: Insulation Tests for Electrical Relays.
255-5:
255-6: Part 6: Measuring Relays with More than One Input Energizing Quantity.
255-6A: First Supplement to Publication 255-6 (1978).

-7
ELECTRICAL RELAYS
Part 13: Biased (percentage) differential relays
SECTION ONE – SCOPE AND DEFINITIONS
1. Scope
This standard specifies the performance requirements of electrically biased (percentage)
differential relays. These relays constitute a particular sub-family of measuring relays with
more than one input energizing quantity as defined in IEC Publication 255-6, Electrical
Relays, Part 6: Measuring Relays with More than One Input Energizing Quantity, and the
parameters whose values are to be declared by the manufacturer of such relays. It also
specifies methods of presentation of the characteristics and performance of these relays.
This standard applies to relays designed for the detection of faults particularly in a.c.
generators, motors and transformers. It does not apply to relays designed for busbar
protection, nor does it apply to current differential (e.g. pilot wire) relays used for the
protection of transrhission lines. This standard covers the majority of biased (percentage)
differential relays and also, for example, those where the restraint percentage increases as the
through-current increases. For particular cases, supplementary requirements may be stated in
national standards.
All tests in this standard are type tests.
This standard applies only to relays in a new condition.
2. Definitions
For definitions of general terms not defined in this standard, reference should be made to
the IEC International Electrotechnical Vocabulary (I.E.V.), to IEC Publication 255-6, and
to IEC Publication 255-6A: First supplement to IEC Publication 255-6 (1978).
For the purpose of this standard, the following definitions shall apply:
2.1 Differential relay
A relay which, by its design, is intended to respond to differential current.
2.2 Biased (or percentage) differential relay
A differential relay in which the designed response is modified by a restraint current.
2.3 Differential current
In a differential relay, a current which is the phasor difference between specified incoming
and outgoing currents.
2.4 Restraint current
In a differential relay, the combination of incoming and outgoing currents, which restrains
operation of the relay.
9 —
2.5 Restraint percentage
The ratio, expressed as a percentage, between the differential current and the restraint
current(s) up to which the relay does not operate.
Note. — The definition of restraint percentage ignores an error, which may not be negligible, due to the finite
operating current required under zero restraint conditions. This may be taken into account when necessary.
2.6 Through current
In a differential relay, that portion of the total incoming current that is also present in the
outgoing current.
SECTION TWO — REQUIREMENTS
3. Standard values
Input and auxiliary energizing quantities and frequency
3.1
The standard values of input and auxiliary energizing quantities, and of frequency, are
specified in IEC Publication 255-6.
3.2 Standard reference values of influencing quantities and factors and standard values of their
nominal and extreme ranges
3.2.1 Influencing quantities and factors
The standard reference conditions are specified in Table I of IEC Publication 255-6. In
addition, the standard conditions given in Table I in this standard apply to biased
(percentage) differential relays.
TABLE I
Standard reference conditions and test tolerances of influencing quantities and factors
Influencing quantity or factor Reference conditions Test tolerances
the manufacturer or as specified in national
Input energizing currents As declared by
– Restraint current standards unless specified in clauses below or in lower-level
– Differential current documents
C. a)
Phase angle between input Zp
o° ±
energizing quantities
u a
U
,- CO
^ 2N
Zero
62-0 Transient
5% of peak a.c. value
(See note)
g d.c. component in a.c.
.2
U
As declared by the manufacturer or as specified in national
Setting value(s), where setting
adjustments are possible standards unless specified in clauses below or in lower-level
documents
Auxiliary Transient
Zero °
energizing d.c. component
/o of peak a.c. value
quantities in a.c. (See note)
Note. — In the special case of relays in which polyphase measurements are made on a single relay, the manufacturer
or national standards shall define which of the input currents shall be under reference conditions.

Limits of the nominal ranges of influencing quantities and factors
3.2.2
The standard values are specified in Table II of I E C Publication 255-6. In addition,
the standard values given in Table II in this standard apply to biased (percentage) differential
relays.
TABLE II
Standard values of the limits of the nominal ranges of influencing quantities and factors
Nominal range
Influencing quantity or factor
Reference input energizing quantity
Non-reference input energizing quantity
.2
Phase angle between input energizing quantities
a"
G
ca z
7.:
As declared by the manufacturer or as
^
specified in national standards
Frequency
c
.N
N
t
Waveform
m G
U
Steady-state d.c. component in a.c.
Transient d.c. component in a.c.
Voltage or current
As declared by the manufacturer or as
specified in national standards unless
_ " Frequency
specified in clauses below
cr Waveform
CL
.E
0 to 12% of the rated d.c. value')
a.c. component in d.c. (ripple)
':1
o
o
T
Steady state d.c. component in a.c.
As declared by the manufacturer or as
specified in national standards unless
specified in clauses below
Transient d.c. component in a.c.
This value of the tolerance is based on the definition given in the International Electrotechnical Vocabulary (I.E.V.
131-03-14) Peak ripple factor.
3.3 Characteristic quantity(ies) and setting range(s)
There are no standard rated values of either characteristic quantity(ies) or setting range(s).
The values and the limits of setting range(s) shall be declared by the manufacturer.
3.4 Restraint percentage
There are no standard values of restraint percentage. The setting values shall be declared
by the manufacturer.
— 13 —
3.5 Resetting and disengaging ratios
There are no standard values of the resetting and disengaging ratios. The values shall be
declared by the manufacturer.
4. Operation and accuracy
4.1 Operation
4.1.1 Operating characteristic
The manufacturer shall declare the operating characteristics of the relay under reference
conditions, these including the reference setting of the differential circuit, and at the maximum
and minimum settings of the restraint circuits, when applicable.
4.1.2 Effective range*
The manufacturer shall declare the effective range * of restraint current values.
4.1.3 Maximum through current
The manufacturer shall declare the maximum through current up to which the relay
produces no output. The relay shall be able to withstand the sudden application and removal
of through current up to this value. This duration shall be declared by the manufacturer
and shall be at least 100 ms.
Note. —
This maximum value is based on a test in which there is no intentional differential current, the incoming and
outgoing (through) currents should be equal.
4.1.4 Harmonic restraint
For relays which have harmonic restraint, the manufacturer shall declare which of the
harmonics have a restraining effect and explain how the harmonic restraint interacts with
the fundamental frequency restraint. The amount of each of these harmonics which will prevent
operation of the relay shall be declared, the amount being expressed as a percentage of the
differential current at the rated frequency. If different values are obtained under steady-state
and dynamic conditions, the highest value shall be stated.
4.2
Accuracy
For biased (percentage) differential relays, considerations of accuracy apply to the operating
characteristics and to the operating time under reference conditions. For these items the
manufacturer shall declare the assigned errors, as defined in I E C Publication 255-6.
4.2.1 Operating characteristics
The accuracy of the operating characteristics may be shown graphically by maximum and
minimum lines, as in Figure 1, page 22. Alternatively, the manufacturer may declare the
restraint percentage, with a plus or minus tolerance, over the effective range of restraint current.
4.2.2 Operating time
The accuracy of the operating times may be shown graphically as in Figure 2, page 22, or it
may be declared by the manufacturer for a specified range of differential currents.
Note. —
Normally only a maximum operating time is specified.
* See also I E C Publication 255-6A, Sub-clause 2.3.

15 —
performance
5. Methods of presenting relay characteristics and
5.1
Operating characteristics
When presenting the operating characteristics of a relay, the manufacturer may use as a
restraint current any combination of incoming and outgoing currents, depending on relay
design.
Figure 1, page 22. shows the recommended method of presenting the operating
characteristics and associated limits. Differential current is shown on the vertical axis and
restraint current on the horizontal axis.
Notes I. — Methods other than graphical may be used for the presentation of the operating characteristics.
2. — Where appropriate, the manufacturer should declare results both on a single and a three-phase basis.
5.2 Operating time
Figure 2, page 22, shows the recommended method of presenting the operating times and
associated limits over a range of currents to be de
...