[Code of Federal Regulations] [Title 30, Volume 1] [Revised as of July 1, 2006] From the U.S. Government Printing Office via GPO Access [CITE: 30CFR77] [Page 646] TITLE 30--MINERAL RESOURCES CHAPTER I--MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR PART 77_MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES--Table of Contents Subpart I_Surface High-Voltage Distribution Sec. 77.800-1 Testing, examination, and maintenance of circuit breakers; procedures. (a) Circuit breakers and their auxiliary devices protecting high- voltage circuits to portable or mobile equipment shall be tested and examined at least once each month by a person qualified as provided in Sec. 77.103. (b) Tests shall include: (1) Breaking continuity of the ground check conductor where ground check monitoring is used; and, (2) Actuating any 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.