scope:

This Technical Report provides recommendations for consistent use of mnemonics and qualifying symbols to be applied to symbols representing devices used in systems for monitoring, protection, switching, and controlling of apparatus in electrical substations, generating stations, power utilization and conversion facilities, and equipment designed for automatic protection of power systems. The recommendations are intended for designers, manufacturers and engineers of such systems.

For symbols of measuring relay and measuring instrument, it is intended to serve two purposes, namely:

- Give a review of standardized designations (as defined in this report);

- Limit the range of possible variants (after final standardization and introduction in IEC 60617).

Symbols for measuring relays are symbols in which the functional behaviour of an element, mostly because of its complexity, is described by qualifying symbols e.g. IEC 60617-S00328 (2001-07), IEC 60617-S00337 (2001-07), particularly by referring to supporting documentation; the relevant rules and explanations are to be found in IEC 60617 in the application notes associated with the symbols, e.g. IEC 60617-S00327 (2001-07) (A00091 through A00094).

Symbols for indicating, recording or integrating instruments are symbols in which the functional behaviour of an element is fully described by standardized means. The relevant rules and explanations are to be found in IEC 60617 in the application notes associated with the symbols IEC 60617-S00910 (2001-07), IEC 60617-S00911 (2001-07) and IEC 60617-S00912 (A00144 through A00147).