IEC 60255-27-2005 pdf – Measuring relays and protection equipment – Part 27: Product safety requirements.
1 Scope and object This International Standard describes the product safety requirements for measuring relays and protection equipment having a rated a.c. voltage up to 1 000 V with a rated frequency up to 65 Hz, or a rated d.c. voltage up to 1 500 V. Above these limits, IEC 60664-1 should be used for the determination of clearance, creepage distance and withstand test voltage. This standard details essential safety requirements to minimize the risk of fire and hazards caused by electric shock or injury to the user. This standard does not cover the safety requirements of installations. It does cover all the ways in which the equipment may be mounted and used in cubicles, racks and panels, and also re-testing. This standard also applies to auxiliary devices such as shunts, series resistors, transformers, etc., solely used and tested together with measuring relays and protection equipment. Ancillary equipment used in conjunction with measuring relays and protection equipment may need to comply with additional safety requirements. This standard is intended to describe only product safety requirements; therefore, functional performance of the equipment is not covered. Functional safety requirements, including EMC functional safety, are not covered by this standard. Functional safety risk analysis is not within the scope of this product safety standard. This standard does not specify individual equipments or implementations of circuits and components. The object of this standard is to have a comprehensive standard that covers all aspects of product safety and the related type and routine tests, for measuring relays and protection equipment.
IEC 60068-2-30:1980, Environmental testing – Part 2: Tests – Test Db and guidance: Damp heat, cyclic (12 + 12-hour cycle) IEC 60068-2-78:2001, Environmental testing – Part 2-78: Tests – Test Cab: Damp heat, steady state IEC 60085: 2004, Electrical insulation – Thermal classification IEC 60127-1:1988, Miniature fuses – Part 1: Definitions for miniature fuses and general requirements for miniature fuse-links IEC 60255-6:1988, Electrical relays – Part 6: Measuring relays and protection equipment IEC 60255-21-1:1988, Electrical relays – Part 21: Vibration, shock, bump and seismic tests on measuring relays and protection equipment – Section One: Vibration tests (sinusoidal) IEC 60255-21-2:1988, Electrical relays – Part 21: Vibration, shock, bump and seismic tests on measuring relays and protection equipment – Section Two: Shock and bump tests IEC 60255-21-3:1993, Electrical relays – Part 21: Vibration, shock, bump and seismic tests on measuring relays and protection equipment – Section 3: Seismic tests IEC 60255-22-5:2002, Electrical relays – Part 22-5: Electrical disturbance tests for measuring relays and protection equipment – Surge immunity test IEC 60352-1:1997, Solderless connections – Part 1: Wrapped connections – General requirements, test methods and practical guidance IEC 60352-2:1990, Solderless connections – Part 2: Solderless crimped connections – General requirements, test methods and practical guidance. IEC 60417-DB:2005, Graphical symbols for use on equipment 1 IEC 60529: 1989, Degrees of protection provided by enclosures (IP Code) Amendment 1 (1999) 2 IEC 60664-1:1992, Insulation coordination for equipment within low-voltage systems – Part 1: Principles, requirements and tests. Amendment 1 (2000) Amendment 2 (2002) 3 IEC 60664-3:2003, Insulation coordination for equipment within low-voltage systems – Part 3: Use of coating, potting or moulding for protection against pollution
3 Terms and definitions For the purposes of this document, the following terms and definitions apply. NOTE For definitions of general terms not defined in this standard, reference should be made to IEC 60664-1, 1.3, and IEC 60050 (151-448). 3.1 accessible (of a part) part which can be touched in normal operational use with a standard rigid or jointed test finger as specified in Annex F [IEV 442-01-15, modified] NOTE 1 Accessible in normal operational use applies mainly to the front of the equipment only, for the purposes of this standard. NOTE 2 A communication circuit/network, which may be connected and taken outside of the cubicle housing, the equipment, or on the front of the panel without the need to open a cover or flap to access it, should be considered to be accessible, i.e. should be PEB, PELV, SELV or equivalent. 3.2 adjacent circuits electric circuits which are separated from the considered circuit by the necessary basic or double/reinforced insulation. Circuits which are separated by far more than double or reinforced insulation are not considered to be adjacent 3.3 ambient temperature temperature, determined under prescribed conditions, of the air surrounding the complete equipment [IEV 441-11-13, modified] NOTE 1 For equipment installed inside an enclosure, it is the temperature of the air outside the enclosure. NOTE 2 The ambient temperature is measured at half the distance from any neighbouring equipment, but not more than 300 mm distance from the equipment case, at middle height of the equipment, protected from direct heat radiation from the equipment.