(under subclass 1) Subject matter relating to systems responsive to a 180 deg. change of phase and also systems responsive to an improper phase sequence.
(1) Note. This subclass relates, for example, to systems responsive to a 180 deg. change of phase and also systems responsive to an improper phase sequence, as for example, when Conductors A, B, and C are connected respectively to phases I, III, II, rather than phases I, II, III.
SEE OR SEARCH THIS CLASS, SUBCLASS:
76, for phase sequence sensing.
85, for quantity comparison to determine a phase fault.
SEE OR SEARCH CLASS
307, Electrical Transmission or Interconnection Systems,
127, for polarity, phase sequence or reverse flow responsive switching systems.
