Fig. 3,073.—Diagram of connections of General Electric low voltage release coil when used with speed limiting device on rotary converter.
There is a multiplicity of types and a classification to be comprehensive, should, as in numerous other cases, be made from several points of view. Accordingly relays may be classified:
1. With respect to the nature of the service performed, as
- a. Protective;
- b. Regulative;
- c. Communicative.
2. With respect to the operating current, as
- a. Alternating current;
- b. Direct current.
3. With respect to the manner of performing their function, as
- a. Circuit opening;
- b. Circuit closing.