Thread: Fuses Vs Circuit Breakers

You mean the ATS breakers that just plug in where the blade fuses go? They look like a great idea.

I know aviation Circuit breakers and they are a lot bigger than blade type fuses, might look cool but to re-wire a Disco 2a with CB's, you would run out of space!

Hay Ewe

I’m sorting out two auxiliary fuse boxes to run all my accessories from my second battery. I’ve been researching circuit breakers as opposed to fuses and what I have found is you need to sauce dedicated automotive breakers due to the ‘trip time’. C/B’s tend to hang on in overload a little longer than fuses.
So dedicated automotive fuses SHOULD be fit for purpose? Expensive? Yes!

As they trip so rarely second hand ones from the wreakers should be fine, but I would hunt down the manual reset jobbies as opposed to the auto reset. They trip for a reason and you would want to find out what was wrong with it before resetting it.

All my aux circuits use a blade fuse style circuit breaker.

They are great. Bit expensive to buy, but great. I too currently have a hard to find, intermittent short. When it blows, a quick delve into the battery box, reset and away I go again!

Vibration may be a problem with breakers as well.

We find faulty breakers fairly regularly,a PITA.At least fuses are simple,don't often blow for no reason.

Fuses are still used in the electrical industry and are more suited than circuit breakers in some applications. It is possible to build different protection characteristics in a fuse as it is possible to build different characteristics in a circuit breaker.
Having said that, automotive applications have different conditions than domestic or industrial installations.
My old Commodore (1981) had circuit breakers on the electric windows. The new Commodore (1994) has fuses. If you are blowing fuses often, you have a problem. Replacing the fuses with circuit breakers will only mean you will be resetting the breakers often and they do have a life.
It may be better to fix the fault. If you don't, eventually, you may be tempted to mechanically lock the breaker so it does not trip which may lead to a claim on your insurance when the wiring catches fire.
But, hey, the wiring fault will be fixed then.

Originally Posted by isuzutoo-eh

Why use circuit breakers rather than fuses?
Because I blew this many fuses between the upper Hunter and Sydney, due to a difficult to replicate occasional fault that turned out to be the hazards switch shorting out somewhere whenever turning to a certain lock and hitting a bump, causing the fuse for the indicators to blow (rather than the hazards fuse). Not to mention that Lucas fuses are a different size to commonly available fuses, which don't quite fit in the fuse holders properly.


Blade fuses would be a step up from cartridge fuses...

argh, this is a familiar story! I have glass fuses as well and they are nothing but pain.