M-750 Series - 36V 310A Dual-Battery Selector & Master Disconnect Switch

Series: M-750
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Littelfuse products are not designed for, and shall not be used for, any purpose (including, without limitation, automotive, military, aerospace, medical, life-saving, life-sustaining or nuclear facility applications, devices intended for surgical implant into the body, or any other application in which the failure or lack of desired operation of the product may result in personal injury, death, or property damage) other than those expressly set forth in applicable Littelfuse product documentation. Warranties granted by Littelfuse shall be deemed void for products used for any purpose not expressly set forth in applicable Littelfuse documentation. Littelfuse shall not be liable for any claims or damages arising out of products used in applications not expressly intended by Littelfuse as set forth in applicable Littelfuse documentation. The sale and use of Littelfuse products is subject to Littelfuse Terms and Conditions of Sale, unless otherwise agreed by Littelfuse. "Littelfuse" includes Littelfuse, Inc., and all of its affiliate entities.

The M-750 Series 36V 310A Dual-Battery Selector & Master Disconnect Switch is ideal for boats, emergency vehicles, buses, heavy trucks, and RVs that use one battery for starting the engine and another battery to power auxiliary loads.

This automotive and marine battery selector switch has single-pole, triple-throw (SP3T) circuitry, which gives you four options: batteries OFF, battery 1 ON, battery 2 ON, or both batteries ON simultaneously.

The battery cutoff position ensures reliable battery disconnection to protect against electrical fire, tampering or theft, and battery drain, while the selector switch positions allow for maximum starting power and backup starting power during emergencies.

Features and Benefits

  • 500A intermittent current at 12V dc for up to 5 minutes and 310A maximum continuous current
  • Single-pole, triple-throw (SP3T) switch allows you to use one of two batteries or both batteries at the same time, which enables maximum starting power
  • Functions either with alternators or generators
  • 3/8"-24 copper studs are solidly machined to the contact plates
  • High-performance rubber O-ring keeps water, dust, and contaminants out
  • Rugged polyester thermoplastic case and large, easy-to-grip knob stand up to impacts
  • Designed with a flange for flush mounting or through-panel mounting
  • Make before break design permits operation through the ON positions with the engine running
  • Available with or without a pilot light circuit
  • UL and CE certified


  • Boats
  • Emergency Vehicles
  • Heavy Trucks
  • Buses
  • RVs

Access specifications, certifications, check availability and order parts below

Catalog #Current Rating (Continuous) in AmpsCurrent Rating (Inrush) in AmpsVoltage Rating MaxCircuitryActuatorContact MaterialHousingSamplesCompare
M-75131050036SPSTBlack KnobEngineering Thermoplastic
M-75031050036SPSTBlack KnobCopperEngineering ThermoplasticOrder
M-750-BP31050036SPSTBlack KnobCopperEngineering ThermoplasticOrder
M-75231050036SPSTBlack KnobEngineering ThermoplasticOrder
M-75331050036SPSTBlack KnobEngineering ThermoplasticOrder
M-75431050036SPSTBlack KnobCopperEngineering ThermoplasticOrder
M-754-0131050036SPSTBlack KnobEngineering Thermoplastic
M-754-BP31050036SPSTBlack KnobCopperEngineering ThermoplasticOrder
Obsolete: 2018 -01-11
Plastic Knob
Obsolete: 2014 -12-20
Plastic Knob
Obsolete: 2015 -01-14
Plastic Knob
Part # Part Description RoHS Pb-free RoHS (2015/ 863/EU) Certificate REACH (SVHC’s) Declaration Halogen Free REACH (SVHC’s) IPC-Material Declaration
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