Circuit Breakers vs Fuses.

[SynCity 2]

my mind keeps changing ever day while i'm trying to save on what amp to get. i know its going to be a sundown. but which one? i was leaning toward the 4500. but the used 3000's looked nice. now the 3500 seem to be offering a little more. so after looking, the 3500's do not have any fuses. i really dont like fuses because when i did, it kept blowing (it was a low amp like maybe 50 or so for the whole system, 3 1000w amps and a yellow top, after the stock battery). so i upgraded it to a 250amp monster fuse, worked perfect. i have seemed to have lost my fuse so someone said "Get a circuit breaker instead". just wondering whats your ideas on Fuses and on Circuit breakers.

[brandonf 9]

my mind keeps changing ever day while i'm trying to save on what amp to get. i know its going to be a sundown. but which one? i was leaning toward the 4500. but the used 3000's looked nice. now the 3500 seem to be offering a little more. so after looking, the 3500's do not have any fuses. i really dont like fuses because when i did, it kept blowing (it was a low amp like maybe 50 or so for the whole system, 3 1000w amps and a yellow top, after the stock battery). so i upgraded it to a 250amp monster fuse, worked perfect. i have seemed to have lost my fuse so someone said "Get a circuit breaker instead". just wondering whats your ideas on Fuses and on Circuit breakers.

http://www.bcae1.com/cirbrakr.htm (love this site):

Circuit Breaker:

A circuit breaker's function is, like a fuse, to break a circuit path when a predetermined amount of current is passed. In my opinion, circuit breakers should never be used to protect electronic devices such as radios, amplifiers or crossovers. Most common circuit breakers (thermal snap action) take far too long to open the circuit path. This does not mean that they are not useful. When they are properly selected they do a good job of protecting wiring and devices such as electric motors. Some breakers are self resetting. Others require manual resetting. I strongly recommend using a manual reset type. This will allow you to watch for any problems when the circuit path is restored.

You may also want to check out proper fusing. I'll be running ~1500-2k watts over 1/0 gauge using a 250amp anl fuse.

[KU40 173]

I would use fuses. Not only for the problem Brandon listed from the bcae1 website, but I've heard people say their circuit breakers develop a bit of a tolerance after being tripped several times. It starts taking more and more juice to trip it. I wouldn't want that.

[djphilly 11]

my mind keeps changing ever day while i'm trying to save on what amp to get. i know its going to be a sundown. but which one? i was leaning toward the 4500. but the used 3000's looked nice. now the 3500 seem to be offering a little more. so after looking, the 3500's do not have any fuses. i really dont like fuses because when i did, it kept blowing (it was a low amp like maybe 50 or so for the whole system, 3 1000w amps and a yellow top, after the stock battery). so i upgraded it to a 250amp monster fuse, worked perfect. i have seemed to have lost my fuse so someone said "Get a circuit breaker instead". just wondering whats your ideas on Fuses and on Circuit breakers.

Circuit breakers are an option, but keep in mind that circuit breakers are acurate to an certain extent. once the breaker trips once, it is not as acurate from there on. I would prefer to do the math and get the correct ANL fuse for what I need.

[jcarter1885 995]

Not a fan of circuit breakers at all, only use fuses in my opinion. Not saying they wont work but like stated above once tripped you always have a problem, no problems with fuses unless you blow them and all you gotta do is replace them.

[///M5 2,833]

Neither should really be tripping anyways so what woudl the benefit of the breaker be?

[SynCity 2]

my mind keeps changing ever day while i'm trying to save on what amp to get. i know its going to be a sundown. but which one? i was leaning toward the 4500. but the used 3000's looked nice. now the 3500 seem to be offering a little more. so after looking, the 3500's do not have any fuses. i really dont like fuses because when i did, it kept blowing (it was a low amp like maybe 50 or so for the whole system, 3 1000w amps and a yellow top, after the stock battery). so i upgraded it to a 250amp monster fuse, worked perfect. i have seemed to have lost my fuse so someone said "Get a circuit breaker instead". just wondering whats your ideas on Fuses and on Circuit breakers.

Circuit breakers are an option, but keep in mind that circuit breakers are acurate to an certain extent. once the breaker trips once, it is not as acurate from there on. I would prefer to do the math and get the correct ANL fuse for what I need.

how do you go upon doing the math for that? *i'm horrible at math*

[KU40 173]

Depends on wire size, what amp(s) used, and if you step down wire size with a distribution block.

[CrazyKenKid 64]

these are not my words! i took them from another forum from a guy named Dukk, he explained it pretty well i thought so i thought i wuold share it on here!

I'll offer this though. As I am sure you know, but others may not, a circuit breaker works by passing current through a strip of two metals laminated together that have different expansion rates when heated. Excess current heats the metals up, they deform in a predictable manner, and the gate is opened within the breaker. This is why a breaker often has to cool down a bit before it can be reset.

In a fuse there is a strip of metal that is either riveted, welded, or soldered to the contacts. Excess current heats up the metal and it melts away, opening the circuit.

If both items function as they should, they perform essentially the same function. Excess heat caused by excess current results in the circuit being opened.

The difference is when they do not function as they should. In a breaker, there are a number of failure modes. The breaker could open as it should and then not re-close or in some other way the contacts are not reattached when closed. No biggie - replace the breaker. Being a mechanical device though, and generally installed in a harsh environment (under the hood) it is conceivable that the breaker could well fail closed. The mechanism could corrode or jam from dirt and debris. Even ice could physically keep the key from opening. The contacts could weld together when the breaker is set, or reset, if the instantaneous current draw is high. The bi-metal strip could delaminate or malfunction in another way and not deform properly, allowing the connection to continue when it should have opened.

A fuse fails in one way, it melts away and opens. The only real failure mode is if it or it's contacts open unnecessarily. While a PITA, it is not threatening. It is impossible for a fuse to fail closed. Ultimately, this is superior protection.

And why do people choose breakers anyway? Are you anticipating multiple events that will require re-setting of the circuit? I haven't changed a fuse in my car in 5 years. Why would I need a breaker? Oh..., maintenance? Just unhook the battery if that's what it takes. So, really, one could go on to argue that a breaker is only superior if one anticipates problems. If this is the case, that's poor design.

Edited November 21, 2009 by CrazyKenKid

[Tirefryr 1,742]

Technically a fuse can fail closed. IT will not pass the needed current but will still show continuity. That's why you always test a fuse for voltage instead of continuity.

[CrazyKenKid 64]

Technically a fuse can fail closed. IT will not pass the needed current but will still show continuity. That's why you always test a fuse for voltage instead of continuity.

good call!

[alexj01_83 6]

i had a circuit breaker worked fine for a while but when it got hot under the hood, and i had the car at idle pounding it would trip too much, went with a fuse and was fine.