100A Continuous 200A Cranking 12V-24V DC Marine Battery Isolator Switch ON-OFF Battery Disconnect Switch for Boat Camper Truck

Most isolator listings give you one number and leave it there. The MT078 publishes the electrical data a workshop or a surveyor actually asks for: not only 100A continuous and 200A cranking at 12V to 24V, but also dielectric strength, contact resistance and insulation resistance.

That matters on a small boat or a camper, where the switch is bolted to a metal panel a few centimetres from the hull, and where a damp locker is normal rather than exceptional. The ON / OFF dial gives a clean mechanical break; the electrical data tells you what happens when the circuit is closed.

• 1500VAC for one minute — A hipot test between the current path and the body. It tells a surveyor or an OEM inspector that the housing will not break down if the switch is mounted close to a metal panel.
• Contact resistance ≤50 mΩ — Measured across a closed contact set. Lower resistance means less heat at the studs when 100A runs through for hours, which is what keeps a terminal from discolouring over a season.
• Insulation resistance ≥100 MΩ — The resistance between the live parts and the housing. This is the number that keeps a damp engine bay from turning into a leakage path to ground.

• Small boat and RIB 12V circuits — Lights, bilge pump, radio and a fish finder from one master dial.
• Caravan and camper 12V distribution — A single hard break ahead of the fuse panel for storage and transport.
• Truck and plant 24V circuits — Kills parasitic drain on vehicles that stand for weeks between jobs.
• Solar and off-grid cabinets — Gives a manual dead point for service work on small 12V or 24V strings.

1. Dial to OFF, negative lead off first — Prove zero volts at both studs before any other work on the circuit.
2. Size cable to 100A continuous — Add margin for run length; treat the 200A cranking figure as a burst, not a working load.
3. Fuse the positive at the battery — The switch gives you a way to break the circuit; the fuse protects the cable between battery and switch.
4. Fix to a flat panel — Use the rear fixing on rigid material so the stud nuts do not work loose under vibration.
5. Torque the lugs and load test — Closed ring lugs only, then check stud temperature by hand after the first loaded run.

MT078, ON / OFF isolator, DC 12V-24V, 100A continuous and 200A cranking, 1500VAC dielectric strength for one minute, contact resistance at or below 50 mΩ and insulation resistance at or above 100 MΩ. There is no minimum order quantity — single units, samples and mixed containers are all accepted, with pricing quoted against quantity and packing. Standard production runs 30 days from deposit; T/T or Western Union, 30% down and the balance before shipment. Units ship in cartons, with pallet lots quoted separately.

Tell us your system voltage, continuous load and mounting position and we will confirm the MT078 configuration, packing and freight for your order — no minimum quantity required.

Tag: Marine Battery Isolator Switch / Marine Isolating Switch / Boat Isolator Switch