ON-OFF Two-Position Rotary Marine Battery Isolator Switch DC 32V with 700A Cranking for Boat Battery Disconnect

Most battery switches advertise one number. The MT072 publishes three, because a boat or a work truck never draws the same current for more than a few minutes at a time. Continuous is 350A, a five-minute window sits at 525A, and a 700A burst is available for cranking. Knowing which figure applies to which job is the difference between a switch that lasts a decade and one that discolours in a season.

The body is rated to DC 32V, which covers 24V nominal systems with headroom for charging voltage, and the dial is a plain two-position rotary — ON or OFF, with a positive stop at each end so the state of the circuit is never in doubt.

• 350A continuous — The cable-sizing figure. A load may sit here indefinitely without the studs heating up.
• 525A for 5 minutes — The one most sellers leave out. Thruster runs, winch pulls and inverter surges have a clock on them — five minutes, then back down to continuous.
• 700A cranking — An engine-start burst measured in seconds. Never a working load, and never the number to size wire against.

Wire the installation to the continuous figure. Quote the cranking figure only when a buyer asks what the switch will survive for two seconds on a cold morning.

• Rotary head with a hard stop — ON and OFF are detents, not a friction fit, so the position holds under engine vibration and can be read by touch in a dark locker.
• Copper current path — A solid copper bridge runs cooler at 350A than plated steel and keeps a clean contact face through years of switching.
• ABS body, sealed joint — Moulded rather than soft-formed, so studs stay square under torque and spray cannot reach the contact set.
• Stud terminals — Sized for closed ring lugs carrying 350A cable; no shaving of strands to make a lug fit.

1. Switch to OFF and disconnect the negative — Prove dead at both studs before touching the positive side.
2. Plan cable against 350A, not 700A — Add margin for run length and bundling, and fuse the positive cable at the battery end.
3. Mount on rigid material — Use the rear base on a flat panel; a flexing surface loosens stud nuts over a season.
4. Land closed ring lugs and torque — Bank positive on one stud, starter or distribution feed on the other.
5. Cycle once off load, then load test — Reconnect, run under load, then check stud temperature by hand.

There is no minimum order quantity on the MT072: single units, sample orders and mixed containers are all accepted, with pricing quoted against quantity and packing. Standard production takes 30 days from deposit. Payment is by T/T or Western Union, 30% down with the balance before shipment. Units are packed in cartons; pallet quantities can be quoted separately.

Heavy but non-cranking loads — a bow thruster burst, a winch pull, an inverter surge. After five minutes at 525A, drop back to 350A so the contacts can shed heat.

Yes. DC 32V covers 24V nominal systems with headroom for charging voltage. Do not use it on 48V circuits.

The usual practice is to break the positive. Follow your surveyor or OEM drawing if it specifies otherwise.

No MOQ on the MT072. Single units and trial orders are accepted, with the price quoted against quantity and packing.

Dial artwork and body marking can be produced to your drawing; the specification is confirmed before production.

Send your system voltage, the largest load you expect and the mounting position, and we will confirm the MT072 configuration and freight for your order — no minimum quantity required.