30 CFR § 75.800-3
Testing, examination and maintenance of circuit breakers; procedures
July 29, 2020
(a) Circuit breakers and their auxiliary devices protecting underground high-voltage circuits shall be tested and examined at least once each month by a person qualified as provided in §75.153;
(b) Tests shall include: (1) Breaking continuity of the ground check conductor, where ground check monitoring is used; and
(2) Actuating at least two (2) of the auxiliary protective relays.
(c) Examination shall include visual observation of all components of the circuit breaker and its auxiliary devices, and such repairs or adjustments as are indicated by such tests and examinations shall be carried out immediately.