Where to Install Circuit Breaker on Trailer

Updated 07/11/2018 | Published 07/09/2018

Products Featured in This Question

30 amp. In-Line Circuit Breaker - Perpendicular Mount Bracket

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$7.35

10 Gauge Wire - Blue Primary - Per Foot

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$1.61

Question:

I have a new trailer that the buyer has requested a circuit breaker be added to the wiring and Im trying to determine where that should be installed.

asked by: David M

Expert Reply:

Generally a circuit breaker should be installed close to the power source. On a trailer with on-board battery power breakers are best installed near the batteries and each circuit should have a breaker of the appropriate amperage value for the device on that circuit.

For example, in a tow vehicle that has a common 7-way wiring setup the 40-amp circuit breaker for the +12V power feed to the trailer is usually mounted to the firewall in the engine compartment and typically this circuit uses a 10-gauge wire like # 10-1-1 to deliver this power to the trailer socket.

On a circuit breaker like # 38630 the zinc chromate (copper-colored) post should connect to the power source.

expert reply by: Adam R