IEC 60255-5:2000 pdf download.Electrical relays – Part 5: Insulation coordination for measuring relays and protection equipment – Requirements and tests
1 Scope and object
This part of IEC 60255 gives general requirements for the insulation coordination of measuring relays and protection equipment.
NOTE 1 Unless otherwise stated, the term “relay(s)” is used as an abbreviation for the expression “measuring relays and protection equipment” in this standard.
In particular, this standard, specifies the following:
– definition of terms;
– guidance for the selection of clearances and creepage distances and other aspects
related to the insulation of measuring relays and protection equipment;
– requirements for voltage tests and insulation resistance measurement.
This standard is applicable to the installation and use at altitudes up to 2 000 m of equipment
having a rated a.c. voltage up to 1 000 V, with a rated frequency up to 65 Hz, or a d.c. voltage
up to 1 500 V.
This standard also applies to associated auxiliary devices such as shunts, series resistors,
transformers, etc., used and tested together with measuring relays and protection equipment
as mentioned above, except where the devices are covered by other IEC publications, for
example communication interfaces.
NOTE 2 Requirements for altitudes exceeding 2 000 m can be derived from table B.1 .
2 Normative references
The following normative documents contain provisions which, through reference in this text,
constitute provisions of this part of IEC 60255. For dated references, subsequent
amendments to, or revisions of, any of these publications do not apply. However, parties to
agreements based on this part of IEC 60255 are encouraged to investigate the possibility of
applying the most recent editions of the normative documents indicated below. For undated
references, the latest edition of the normative document referred to applies. Members of ISO
and IEC maintain registers of currently valid International Standards.
IEC 60050(1 51 ):1 978, International Electrotechnical Vocabulary (IEV) – Chapter 1 51 : Electrical and magnetic devices
IEC 60050(448):1 995, International Electrotechnical Vocabulary – Chapter 448: Power system protection
IEC 60060-1 :1 989, High-voltage test techniques – Part 1 : General definitions and test requirements
IEC 60085:1 984, Thermal evaluation and classification of electrical insulation
IEC 601 1 2:1 979, Method for determining the comparative and the proof tracking indices of
solid insulating materials under moist conditions
IEC 60255 (all parts), Electrical relays
IEC 60255-21 -1 :1 988, Electrical relays – Part 21 : Vibration, shock, bump and seismic tests on
measuring relays and protection equipment – Section 1 : Vibration tests (sinusoidal)
IEC 60255-21 -2:1 988, Electrical relays – Part 21 : Vibration, shock, bump and seismic tests on
measuring relays and protection equipment – Section 2: Shock and bump tests
IEC 60255-21 -3:1 993, Electrical relays – Part 21 : Vibration, shock, bump and seismic tests on
measuring relays and protection equipment – Section 3: Seismic tests
IEC 60664-1 :1 992, Insulation coordination for equipment within low-voltage systems – Part 1 :
Principles, requirements and tests
IEC 61 000-4-5:1 995, Electromagnetic compatibility (EMC) – Part 4: Testing and measurement
techniques – Section 5: Surge immunity test
IEC 61 1 80-1 :1 992, High-voltage test techniques for low-voltage equipment – Part 1 :
Definitions and test procedure requirements
IEC 61 1 80-2:1 994, High-voltage test techniques for low-voltage equipment – Part 2: Test
equipment
3 Definitions
For the purpose of this part of IEC 60255, the following definitions together with those of
IEC 60050(448), IEC 60664-1 and the relevant parts of IEC 60255 apply.
3.1 hazardous live part
part at a voltage in excess of 50 V r.m.s. or 75 V d.c.
3.2 exposed conductive part
conductive part which can be readily touched and is normally not hazardous live but may be
at hazardous live voltage under a single fault condition
NOTE 1 For relays which are not enclosed, the frame, the fixing devices, etc., form the exposed conductive parts.
NOTE 2 For relays which are enclosed, the conductive parts which are accessible when the relay is mounted in its normal position of use, including those of its fixing surface, form the exposed conductive parts. Small parts such as inscription plates, screws and rivets which are isolated from the circuits are not taken into consideration.
3.3 clearance
shortest distance in air between two conductive parts [IEC 60664-1 ]
3.4 solid insulation
solid insulating material interposed between any two conductive parts [IEC 60664-1 ]
IEC 60255-5:2000 pdf download
