Skip to content
§ 75.1910 (a), (b), (c), (d), (e), and (f) Electrical Protection of Starting Circuits on Diesel Engines


General Information


Please read all the information in this Section before applying a fuse or circuit breaker to a diesel engine start circuit arrangement. For assistance, contact MSHA's Approval and Certification Center at 304-547-0400, between 8:00am and 4:30pm EST.


Title 30 Code of Federal Regulations (30CFR) Sections 75.1910(a), 75.1910(b), 75.1910(c), 75.1910(d), 75.1910(e), and 75.1910(f) provides the requirements for overcurrent protection of electrical circuits on nonpermissible outby diesel-powered equipment directly using storage batteries and integral charging systems. These sections refer to Sections 75.518 and 75.518-1 for adequate overload and short circuit protection on the equipment. Sections 75.518 and 75.518-1 refer to the 1968 National Electrical Code (NEC). Overload and short circuit protections of electrical circuits and components on outby diesel-powered equipment are adequate when they meet or exceed the safety requirements in the 1968 NEC.


The following list is one method for selecting short circuit and overload protection to comply with the regulation. The list may be used by mine operators to comply with Section 75.1910.


This method works only when all specified components are applied as a group.


The list consists of engines, batteries, battery cables, fuses, circuit breakers, and available circuit interrupters. A row of components must be applied as a group to comply with Section 75.1910. A Nuisance Tripping and Trouble Shooting Guide and starter circuit wiring diagrams are also provided. Wiring diagrams are provided for installing the circuit interrupters, circuit breakers, and fuses.


All batteries are heavy duty or commercial batteries and are a significant factor in the application of the fuses and circuit breakers using this method. The battery size in cold cranking amps (CCA) and battery cable size must be maintained as listed to insure that the fuses and/or circuit breakers will function when necessary. Only listed batteries are acceptable when using this method of compliance.


Alternate batteries may be substituted for the listed battery only as follows:


125Amp or less Fuses and CB's

150Amp or greater Fuses and CB's

Odyssey PC1700

Odyssey PC2150

Group 31, 950CCA



When two batteries are listed, two of the same size battery (in CCA) must be used.


All starters must be original equipment starters or complete high quality rebuilds. Partially rebuilt starters are highly susceptible to nuisance tripping.


Note: For questions or comments contact the Approval and Certification Center, RR1, Box 251, Industrial Park Road, Triadelphia, WV 26059. Phone (304) 547-0400.

Available Resources

  • AM General
  • Caterpillar
  • Cummins
  • Deutz
  • Farymann
  • Ford
  • Isuzu
  • Kubota
  • Lister-Petter
  • Mercedes
  • Mitsubishi
  • Perkins
  • Wiring Diagram No. 1
  • Wiring Diagram No. 2
  • Wiring Diagram No. 3
  • Wiring Diagram No. 4
  • Available Circuit Interrupters
  • Nuisance Tripping and Trouble Shooting Guide
  • Distributors