Circuit Breaker Replacement

[Tom Wood]

I am looking for a 120-volt, 15-amp AMF circuit breaker for a 17-year old Chinese-built sloop by Litton. Any ideas on where I can find these?

Tom Wood responds:

Perhaps I am missing something, and I know I will get all kinds of mail from electrical engineers, but a circuit breaker is a circuit breaker. Yes, I know that the great debate between the proponents of thermal and magnetic breakers, and even the supporters of dual mode and a few vacuum fanatics, rages on. But for all practical purposes, any overload safety device that opens the circuit in case of a short will do the job.

Almost all circuit breakers found on boats are of the thermal variety. Regardless of the name of the distributor pasted on the side, the bulk of them are built by Airpac in Mexico or by Carlingswitch. There are many, many companies building circuit breakers, however, including industry giants such as Siemens, General Electric, and Square D. A 120-volt, 15-amp breaker should not be a hard-to-find item.

With one possible exception, of course. Since most boat builders buy pre-wired panels from marine distributors that use Airpac breakers, the holes in the panel for the handle and mounting screws, as well as the position of the buss bar in the back of the panel, are made to fit these breakers. If your boat has breakers with nonstandard mounting holes and you have a defective one, you have three choices:

1.  Search until you find a breaker that fits the panel.

2.  Jury-jig an available breaker to fit the spot.

3.  Replace the whole panel with one for which you can buy parts in the future.

The Chinese, by the way, are masters at making exact copies of American and European goods, giving them solid, English-sounding names to make you think they were made in the UK or Australia. The good news is that their copies are often so intricately correct that an American replacement part slips into the same mounting holes as its Chinese-made copy. Now, all you have to do is find out from which brand of circuit breaker the design was copied. Good luck.