Scope and objectThis standard specifies the general performance requirements of all electrical measuring relays and protection equipment used in the electrotechnical fields covered by the IEC. It excludes relays used in the following electrotechnical fields:- telephony;- telegraphy;- signalling and blocking in railway systems;- devices covered by IEC Publications 158@ 292 and 337.For special applications (marine@ aerospace@ explosive atmospheres@ computers@ etc.)@ it may be amplified by means of special requirements.Relays which are designed to meet the requirements prepared by other international standardization organizations (telecommunication@ railways@ etc.) shall comply with this standard when used in the electrotechnical fields covered by the IEC @ other than those excluded above.The requirements are applicable only to relays in new condition. All tests in this standard are type tests unless otherwise declared.The object of this standard is to state:1) definitions of terms used;2) nominal values relating to energizing and influencing quantities;3) requirements related to accuracy@ thermal and mechanical performance;4) test methods;5 ) markings and data.