Fuses versus Breakers (CRJ-200 and others)

C150J

C150J

Well-Known Member
Please excuse my inferior knowledge of electrical systems:

The CRJ-200 has 4 fuses (all DC ESS bus related) and the rest are CBs...

Why? Is the only difference between a fuse and a breaker the ability to reset?
 
A fuse is a one time deal, if it is over loaded it burns out. You find them in some electronics in the plug and you pull them out and they look like a small glass cylinder with a metal piece on either end. They can not be reset.

A breaker on the other hand can be.

Edit: From my understanding fuses are less likely to fail in the sense that a CB can break and allow an overload. If a fuse breaks it needs to be replaced and thus unless too large a fuse is used it will never allow an overload, or more rarely than a CB at least.
 
shdw said:
A fuse is a one time deal, if it is over loaded it burns out. You find them in some electronics in the plug and you pull them out and they look like a small glass cylinder with a metal piece on either end. They can not be reset.

A breaker on the other hand can be.

Edit: From my understanding fuses are less likely to fail in the sense that a CB can break and allow an overload. If a fuse breaks it needs to be replaced and thus unless too large a fuse is used it will never allow an overload, or more rarely than a CB at least.
Click to expand...


Hate to be nit-picky with ya, but that is only one type of fuse. There are hundreds of fuse types. Some are even resetable.

Edit: And you were catching up.
 
mshunter said:
Hate to be nit-picky with ya, but that is only one type of fuse. There are hundreds of fuse types. Some are even resetable.

Edit: And you were catching up.
Click to expand...

I hate to boost your post count! But what types of fuses are resetable and can you link it up? I was unfamiliar they could be reset or reused, isn't a fuse a type of material which burns up when it is overloaded? I did some googling and found a patent for a reusable fuse but it talks about changing the filament inside so you don't have to replace the fuses casing.
 
shdw said:
I hate to boost your post count! But what types of fuses are resetable and can you link it up? I was unfamiliar they could be reset or reused, isn't a fuse a type of material which burns up when it is overloaded? I did some googling and found a patent for a reusable fuse but it talks about changing the filament inside so you don't have to replace the fuses casing.
Click to expand...


It's nothing special realy. Just a circut breaker that fits into a fuse slot. The most common are the kind you see in a car (the blade type, from mini lo-pro to maxi). Stop buy a local autoparts store and ask the counter guy.

Here is a link: http://www.cooperbussmann.com/6/BladeFusesandAccessories.html
 
tgrayson said:
In addition to what shdw said, my understanding is that 1) fuses are faster, and 2) fuses are more reliable.
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They do make a special type of fuse, what I've heard called, "Slow Blow" which will not be an instantaneous electrical disconnect.

A good example of a place to use that is on the circuit protection for a generator in an airplane with a starter/generator. The transient loads will be much higher amperage than the system is normally designed for. So the initial draw off the generator when it is switched on after a battery start will be way over the normal amp limit. The "slow blow" fuse will allow the system to surge a bit prior to the load returning to normal. Should you have a NiCad that has an issue, the amperage will stay too high for too long, then the circuit will need to be severed.

IIRC, the KingAirs have this type of fuse in the use described above. However, I'm drawing from memories of many airplane types and many years ago.
 
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