This part of IEC 1812 applies to specified time relays, such as time delay relays, in accordance with definitions as laid down in IEC 50(446), for use in industrial applications (e.g. control, automation, signal and industrial equipment).
The term "relay" as used in this standard comprises all types of relays, other than measuring relays, with specified time function.
Depending on the field of application of these relays (e.g. for electricity generation, transmission and distribution), further standards may be applicable.