M-751 - M-750 Series

Series: M-750
Obsolete: 2015 -01-21 Availability: Obsolete


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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.

For any vehicle that needs to use two batteries where one battery is used for starting the engine. while the other is used to power auxiliary loads. This is a common situation in trucks. boats. RVs. police and rescue vehicles. and in ambulances or fire equipment. A selector switch allows use of the first battery. the second battery. or both batteries simultaneously. This provides back-up starting power in an emergency.


These switches combine the functions of Battery Selector and Master Disconnect Switches to give four battery power options:
  • Power cut off at the source
  • Power On. Battery 2
  • Power On. Battery 1
  • Power On. both Batteries

Battery selector switches provide a positive battery disconnect. which has many advantages:
  • It gives a reliable shutdown of power during maintenance
  • The version with the key protects against theft of the vehicle. when unattended
  • It helps protect against electrical fires. when the vehicle is not in use. and minimizes battery drain


  • Rating: 500A intermittent. 310A continuous. 6-36V DC Electrical ratings on UL labels are conservative. Electrical Ratings Labeled UL 707B
  • Use with either alternators or generators.
Make before break design permits operation through the three On positions with the engines running. Engines should always be shut down before turning to Off.

Heavy-Duty Construction Vaporproof. weather-. dust- and corrosion-resistant.
Durable. fracture-resistant high temperature plastic case. knob and insulator.
Switches conform to USCG section 183.410 for ignition protection.
Resistant to impact. and temperature extremes.
Heavy duty copper stud terminals. with brass hexnuts.
Can be surface mounted. or installed through a 3 5/16"" diameter hole in the panel.
Dimensions: Flange: 6"" (152.4mm) diameter. overall height 2 5/8"" (66.7mm).
Terminals: 3 copper studs. 3/8"" (9.5mm) diameter. Offsite info on Marine Power Generation Offsite info on Marine Dual Battery Wiring
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