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Fuses -V- Circuit breakers
plentywahalla - 26/6/11 at 06:14 PM

Why do car manufacturers still use fuses to protect circuits?

Domestic wiring is all protected by circuit breakers today, fuses are ancient technology. On boats we have been fitting circuit breakers for years too, fuses are considered cheap low tech.

Circuit breakers give exactly the same protection, PLUS you don't have to scrabble about in the bottom of your tool box trying to find a replacement! Also you can simply switch on and off for fault finding etc.

I am partly motivated by the fact I have about 100 or so assorted CarlingSwitch miniature C/B's from 5 to 60 amp in stock and am tempted to use them in my build.

Am I missing something?? ... what would IVA inspectors think?

britishtrident - 26/6/11 at 06:20 PM

From the Silver Shadow onwards Rolls Royce used Cbs on some circuits

rusty nuts - 26/6/11 at 06:24 PM

I think I can sum it up in one word. CHEAP

Ben_Copeland - 26/6/11 at 06:24 PM

Costs money to change things, that in there eye's doesnt need changing.

Additional weight maybe,

Plus they can charge people for replacing the fuses when they go.

Macbeast - 26/6/11 at 06:37 PM

My Focus has 40 or 50 fuses which cost pence each. And how often does a fuse blow in normal service ? 50 fuses dont take up much room whereas 50 breakers would take a lot more.

plentywahalla - 26/6/11 at 06:51 PM

quote:
Originally posted by Macbeast
My Focus has 40 or 50 fuses which cost pence each. And how often does a fuse blow in normal service ? 50 fuses dont take up much room whereas 50 breakers would take a lot more.


A 7 type only needs about 12 circuits. These breakers are only 2cms x 3cms and 1 cm wide so a bank of 12 would take up no more space than a typical fuse panel. Its the connections, loom etc that take up most of the space.

Macbeast - 26/6/11 at 07:38 PM

But the OP was talking about car maufacturers, not Sevens.

JoelP - 26/6/11 at 07:59 PM

cost and size, as has been said. They rarely blow, are easy to swap, and spares dont take up much space either. Plus simplicity equals reliability.

JoelP - 26/6/11 at 08:01 PM

quote:
Originally posted by Macbeast
But the OP was talking about car maufacturers, not Sevens.



he was the OP

SteveWalker - 26/6/11 at 09:20 PM

You can buy circuit breakers that are a direct replacement for the blade type fuses used in most cars - unfortunately they don't fit all boxes due to the slightly taller and wider top. I don't know where you get them, but I was given a handful 15 or so years ago. All manufacturers need to do to enable use of these is wait for their next design, add a few mm to the fusebox lid and widen the top third of each slot.

snakebelly - 27/6/11 at 10:24 AM

We run circuit breakers in our race car so the driver can try a reset on track rather than bin a session/race and come in to change a fuse. We use ETA breakers and they do loads of automotive type. I have their catalogue and its about 1/2" thick! Their website is:
ETA Circuit Breakers

plentywahalla - 27/6/11 at 08:36 PM

quote:
Originally posted by snakebelly
We run circuit breakers in our race car so the driver can try a reset on track rather than bin a session/race and come in to change a fuse. We use ETA breakers and they do loads of automotive type. I have their catalogue and its about 1/2" thick! Their website is:
ETA Circuit Breakers


Thanks Snakebelly and SteveWalker. Your input backs up my thinking exactly.

The C/B's I have are just like the ETA units, lightweight and compact. The breaker panel will take up no more space and weigh no more than fuse holders, so I will definately go for it.