Thread: Fuses Vs Circuit Breakers

I would hazard a guess that fuses are used to reduce costs. Breakers are used in some circuits in cars. I have owned Fords that use a breaker for the headlights and SWMBO fairlane has one in the fuse box although I can't remember for what.

I don't find fuses a problem, as modern cars have pretty good wiring and rarely blow fuses. This even applies to my 96 tdi. Disco.

As for using circuit breakers to replace a fuse I can't see any reason why not.

Dave.

"Co$t"

Fuses do the job fine. why gold plate it?
I have only ever lost a couple of fuses in almost 12 years ownership of my RRC and both were caused by exceptional circumstances, one being the Long range tank wearing through the number plate wires, a second getting the rear bumper plug under muddy water or watery mud? In each case once I had worked out the problem it was just a case of replacing the fuse.
Oh and I just blew the maxi blade I have in the rear circuit because my new compressor draws 45 amps and I had a 30amp fuse in there. A good reminder to get some more 60amp maxis.
It is not something that happens regularly and if it is then you should start looking in the loom as that is the way cars burn to the ground.
Regard sPhilip A

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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...

if i ever turn my Disco into a hybrid (put a series cab and a tray on it) then I will put breakers in and all in one location as they are much better as you say but I couldn't be bothered with the hassle of swapping as it is running like a dream and it is a lot of buggerising about.

Don't just assume that a circuit breaker of the same rating as a fuse will do the same job in protecting downstream loads.
Some CBs will carry a high current (i.e. close to or at their rated trip current) for considerable time before tripping. Sensitive things like electronics can be damaged before it trips.
There are various "curves" for breakers, which dictate their characteristics of time vs. current.

Originally Posted by scanfor

Don't just assume that a circuit breaker of the same rating as a fuse will do the same job in protecting downstream loads.
Some CBs will carry a high current (i.e. close to or at their rated trip current) for considerable time before tripping. Sensitive things like electronics can be damaged before it trips.
There are various "curves" for breakers, which dictate their characteristics of time vs. current.

In A/C there is B, C and D type breakers the instantaneous tripping times are 400%, 750% and 1250% respectively. DC would have similar sorts of breakers for the different intended uses of them

Breakers are used because they are much more accurate in tripping than a fuse. Instantaneous tripping time if a CB is 0.4 of a second where a fuse can be up to 5 seconds, both a fuse and a C/B are designed to operate at 100% of rating.

The blade fuses in the Defender are an absolute bastard to fit and remove, I hate them.