OEX ACX1843 50A Type III Heavy Duty Manual Reset Circuit Breaker - Single Pack

OEX ACX1843 50A Type III Heavy Duty Switchable Manual Reset Circuit Breaker IP67 9.5mm Studs Up to 72VDC

The OEX ACX1843 is a 50A Type III heavy duty manual reset circuit breaker a step up from the ACX1842 (30A) with a higher 50A current rating, larger 9.5mm stainless steel studs and an expanded voltage range up to 72VDC covering 12V, 24V and 48V electrical systems. The Type III switchable design allows the breaker to function as both a circuit breaker and a manual on/off isolation switch. IP67 waterproof and dustproof. Covered by a one year warranty.

Product overview

The ACX1843 builds on the ACX1842 with three meaningful upgrades for high-current and high-voltage applications. The 50A current rating suits large winches, dual battery main feeds, solar charge controller protection and heavy-draw accessory panels that exceed the 30A limit of the ACX1842. The 9.5mm stainless steel studs (up from 8mm) accommodate heavier gauge cable lugs for high-current connections. The expanded voltage range up to 72VDC covers 12V, 24V and 48V electrical systems, including solar, dual battery and EV auxiliary circuits where the ACX1842's 12V/24V rating would not be sufficient.

The Type III switchable classification adds an isolation function the breaker can be manually opened and closed to switch the circuit on and off, in addition to providing overcurrent protection. This makes it more versatile than a standard manual reset breaker in applications where circuit isolation is also needed. The IP67 housing provides complete dust exclusion and protection against temporary water immersion, suited to external, underbonnet, deck-mounted and off-road installations across 4WD, marine, agricultural, mining and commercial vehicle applications.

Features and benefits

Type III switchable circuit breaker and isolation switch: Functions as both a manual reset circuit breaker and a manual on/off isolation switch, adding versatility over a standard manual reset breaker.

50A heavy duty rating: Higher capacity than the ACX1842 (30A), suited to large winches, dual battery main feeds, solar charge controller protection and heavy-draw accessory circuits.

Up to 72VDC: Wide voltage range covering 12V, 24V and 48V electrical systems, including solar, dual battery and EV auxiliary circuits.

9.5mm stainless steel studs: Larger stud size than the ACX1842 (8mm), accommodating heavier gauge cable lugs for high-current connections.

IP67 waterproof and dustproof: Complete dust exclusion and temporary water immersion rating, suited to exposed, external and marine installations.

Rubber stud caps: Protect stud terminals from moisture, contamination and accidental short circuit.

Manual reset: Requires deliberate operator action to restore the circuit after a trip, ensuring the fault is identified before re-energising.

One year warranty: Covered by a one year OEX warranty.

Technical specs

Frequently asked questions

What does "Type III switchable" mean? A Type III manual reset circuit breaker can also function as a manual on/off switch, allowing the operator to manually open and close the circuit in addition to providing overcurrent protection. This adds isolation functionality not available in a standard manual reset breaker.

How does the ACX1843 differ from the ACX1842? The ACX1843 is rated at 50A versus 30A for the ACX1842, uses larger 9.5mm stainless studs versus 8mm, supports up to 72VDC versus 12V/24V, and is Type III switchable. Both are IP67 rated manual reset breakers. Select the ACX1843 for higher-current, higher-voltage or applications requiring an isolation switch function.

What voltage systems does this suit? Up to 72VDC covers 12V, 24V and 48V electrical systems including solar, dual battery, marine and EV auxiliary circuits.

What wire gauge suits a 50A circuit breaker? A minimum of 6mm² (approximately 9AWG or 10 B&S) automotive grade cable is typically recommended for 50A continuous circuits up to approximately 5 metres. For longer runs or high-duty-cycle use, upsize to 8mm² or larger. Always match wire gauge to both the current draw and the cable run length.

Where should this circuit breaker be installed? As close as practical to the power source ideally within 300mm of the battery terminal or distribution point to minimise the length of unprotected cable between the battery and the breaker.