The standard in this publication is the first revision of the American Standard for Relays Associated with Power Switchgear, C37.1-1937. A proposed revision, dated January 12, 1949, was prepared by the American Institute of Electrical Engineers Relay Committee and then submitted to the American Standards Association, Incorporated. Subsequent work on the proposed standard was carried on by the Sectional Committee on Power Switchgear, C37.
The standard relates only to relays of types directly associated with power switchgear. It does not
cover relays of types designed primarily for industrial control, excitation, or governor regulating, telephone, telegraph, traffic signal, or similar purpose.