# Fuses vs Circuit Breakers - does it really matter?



## rob feature (Nov 15, 2015)

I'm getting ready to re-wire my vehicle and thinking about ways I want to approach different problems. One of those is the fusing. Or lack of. Is there any good reason to choose a fuse over breakers - especially under the hood? It will be cheaper and use less room to fuse at the amps (as far as I know), but under the hood it's working out to be about the same price and I'd never need to worry about replacing fuses. And it might give me a little more in the way of installation flexibility. 

Are there failure concerns to consider regarding breakers?  Delay issues? Does it really matter one way or another (price ignored)?


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## DDFusionV2 (Jul 11, 2016)

I've seen them corrode under the hood. That's a failure waiting to happen


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## Theslaking (Oct 8, 2013)

I have used breakers under my hood for 20 years and never had one fail. They definitely have a higher tolerance for popping. For instance if you get a 100a and give it a sort burst of 125 it might not flip aftet it gets old. Fuses do this as well just not usually as high. If you buy a quality breaker and understand it only has so many "flips" in it's intended life cycle you will be fine. If you want to just have the ability to quickly stop the power quickly you could use a fuse and add one of those marine power wire keys. They go inline and work like a faucet letting flow pass with a turn or stop with a turn the other way.


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## Theslaking (Oct 8, 2013)

DDFusionV2 said:


> I've seen them corrode under the hood. That's a failure waiting to happen


I've seen fuses corrode sitting on a shelf. Shouldn't use them either.


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## SPLEclipse (Aug 17, 2012)

I've used a cheap 120A breaker under the hood for my "car side" wiring (fuse box, starter, etc) for a couple of years with no issue. I chose a breaker because it makes it easy for me to disconnect all power to the car if I need to do maintenance.


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## cms983 (Jul 11, 2015)

Just switched to a breaker myself. Nice to have that quick disconnect at the push of a button. Never had issues with fuses either though. 

Sent from my HTC6545LVW using Tapatalk


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## Victor_inox (Apr 27, 2012)

breakers works just fine.
Don`t forget to keep power on your car computer unless it`s old.
many modern cars required constant current. not just for radio but ECU memory.


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## rob feature (Nov 15, 2015)

You know, I never really considered maintenance, but that would be a plus. I think I'd keep the truck's power as-is though, as Victor mentions, and just use the breaker on the amps. This is an older OBDII vehicle (2003), but resetting the clock, losing the trip odometers, and all the settings on the head unit gets old. 

Corrosion (and subsequent failure) was a consideration as de-icer is something I encounter plenty of each Winter. I could always use a marine unit to combat that though. Stinger makes some marine units - might try one of those. 

Thanks for all the advice so far!


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## Theslaking (Oct 8, 2013)

This particular one has been in my truck for 6+ years. I live in in salt road capitol, USA. As you can see the brass is still shiny! The wire looks a little old but the breaker is in good shape. I have changed systems at least 10 times. Amps and accessories many more times. That is a lot of flips and still holding strong.


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## seafish (Aug 1, 2012)

I am not sure if Stinger or RF make their own circuit breakers and/or fuses or simply outsource and/or rebrand another companies devices. Probably the former. That being said, Blue Seas designs and manufactures marine quality electrcial distribution devices, including circuit breakers of various capacities. Available even through amazon..lol.


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## Matthew Borgardt (Aug 13, 2016)

A breaker by design is a a resistor designed to heat up and then reset... a large fuse is a better choice than a breaker... Now if you go by a high quality breaker which will cost you a lot of money, that would not be a bad choice... 
Remember the prime reason why we put a fuse or breaker under hood is to protect the power line, with that said you should put in at least twice the rated fusing of your amplifiersup front... because most amplifiers have fuses built in and that will be your protection for your amp.

Matt Borgardt
Oncore/Cadence/Logic


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## rob feature (Nov 15, 2015)

seafish said:


> I am not sure if Stinger or RF make their own circuit breakers and/or fuses or simply outsource and/or rebrand another companies devices. Probably the former. That being said, Blue Seas designs and manufactures marine quality electrcial distribution devices, including circuit breakers of various capacities. Available even through amazon..lol.


Thanks for the heads up on Blue Sea. I've seen their stuff before, but never paid much attention. Pricey though - another vote for a fuse :laugh:



Matthew Borgardt said:


> A breaker by design is a a resistor designed to heat up and then reset... a large fuse is a better choice than a breaker... Now if you go by a high quality breaker which will cost you a lot of money, that would not be a bad choice...
> Remember the prime reason why we put a fuse or breaker under hood is to protect the power line, with that said you should put in at least twice the rated fusing of your amplifiersup front... because most amplifiers have fuses built in and that will be your protection for your amp.
> 
> Matt Borgardt
> Oncore/Cadence/Logic


I take this to mean that a breaker might allow too much time to pass before cutting the power. And yeah, I'm finding that 'nicer' breakers are getting pretty expensive. Yet another nod to a fuse.

One of my amps has an internal fuse and the other doesn't (XD 400/4), so I'm using a block right in front of the amps as well at manufacturer's spec. Never thought about doubling the rating up front, but thanks for the tip!


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## Lockjaw (Sep 13, 2016)

I use breakers because I always find a way to shoot myself in the foot by blowing fuses


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## ugnlol (Apr 14, 2010)

Lockjaw said:


> I use breakers because I always find a way to shoot myself in the foot by blowing fuses


Sounds like you avoided to solve the problem


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## smgreen20 (Oct 13, 2006)

To say that breakers have so many pops is the same as saying that a human being has so many breaths in life to take. Both are unknown and a crap shoot, lol.

That is also the reason to look at higher quality breakers if you go that route. I did it for a few reasons. 
1) Quick disconnect of the power
2) I got real tired of replacing fuses all of the time due to the solder joints becoming weak and loosing contact. In the long run, I saved money switching to a breaker.

To add to what Matt said, you fuse the wire in a system, not your amps/system. I will argue that you do not need twice the fusing of your amps current demands. 
1) You're fusing the wire to its rated capacity at its given length/gauge. Now more then!
2) It's simply pointless to fuse more then the manufacturer rated fusing as ..... You're only fusing the wire, but provides some protection to the amp/system itself.

If your wire at the given length/gauge is capable of handling 150A of current, but your amps total 100A (manufacturer rated), fuse to the 100A. It's still a better way to protect the wire. Why subject the wire to 150+A of current due to a fault when you can do far less damage at 100A?


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## gijoe (Mar 25, 2008)

You may have your reasons for wanting a breaker, instead of a fuse. But, if one of those reasons is that you don't want to keep replacing fuses, then you should be wondering why you keep blowing fuses. Fuses don't just pop, they only pop if you're doing something dumb (or potentially major equipment failure). There is no reason to think that will a proper install that you'll ever have to change out the fuse. 

A breaker is nice if you intend to work on the system often, and you just want to flip a switch. But again, you should really never need to replace a fuse. If you have a quality fuse holder, and it's properly secured, that fuse will stay put for the life of the system.


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## Alrojoca (Oct 5, 2012)

I've never blown a fuse, the breaker is convenient, it would cost about 10-15 extra dollars. Most likely if it blows it will be a short.

It depends on well you feel about that spark and smoke you get when you connect the fuse. When you remove it, no spark, only when you connect it, the main thing is to be quick, loose screws while holding it down on the block, then pull it.

Connecting it, pick a side you will use to remove and connect it last, since that side will take the spark and leave marks if it is gold or chrome finish plated.

TSPEC has inline fuses that are smoke black color, ha ha, that way you won't noticed the black marks or smoked areas on the finish it does every time you connect a fuse. And it maybe only 10 seconds extra to use a fuse instead of a breaker, maybe the 10-15 secs is worth the extra 10-15 dollars for the breaker


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## smgreen20 (Oct 13, 2006)

The round glass fuses suck. The solder gets weak over time/use and it is then more like cold solder joint. At low volumes, everything is ok. Turn up the volume and then it starts to cut out. If you continuity test them, they test good due to the low voltage/current draw. When that current goes up, it breaks contact, thus acting like a breaker. I now use (and have for the last 8 years) only wafer fuses.


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## rob feature (Nov 15, 2015)

Alrojoca said:


> I've never blown a fuse...


Me neither now that you mention it. Err, I've popped fuses doing stupid things (and the fuses did their jobs), but never from normal use.


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## gijoe (Mar 25, 2008)

rob feature said:


> Me neither now that you mention it. Err, I've popped fuses doing stupid things (and the fuses did their jobs), but never from normal use.


That was my point. I get that a circuit breaker has it's convenience, but if you're motivated by not having to replace fuses all the time, I think you're trying to fight a problem that doesn't exist. I've not priced out what a good quality, useful circuit breaker costs, but I suspect they are significantly more than a decent fuse holder and a fuse.


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## rob feature (Nov 15, 2015)

gijoe said:


> I've not priced out what a good quality, useful circuit breaker costs, but I suspect they are significantly more than a decent fuse holder and a fuse.


Yep, that's what I'm finding


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## Alrojoca (Oct 5, 2012)

ANL, MANL (AFS) is the way to go, blade or maxi fuses are nice, some of the holders may be pricey compared to ANL.

I prefer ANL MANL, with hex screw over philips for the wire, and to hold the wire, Tsunami formely named and now known as TSPEC used hex screws to hold the fuse also. Now simply use a penny or coin and the screw is bigger.

I had a 4 gauge in line fuse from Tsunami, now a TSPEC 0 gauge ANL, sadly the blocks where the fuse seats, are bigger and larger than the 0 gauge in line fuse. They don't make them like they used to. 

Then some question ANL versus MANL, ANL has fuses up to 350 amps, MANL usually stops at 200-250 amps, ANL being bigger may have more surface contact for current, but it is wider and longer, if extra room is available ANL for upgrades or more fuses availability, and usually lower cost, and better looking too.


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## lynchknot (Sep 27, 2014)

I prefer to use ring terminals on my cable ends so I use one like this: https://www.amazon.com/XSCORPION-CB...id=1473899605&sr=1-3&keywords=circuit+breaker or https://www.amazon.com/dp/B01HDX3YXG?psc=1

#1 best seller: https://www.amazon.com/Bussmann-CB1...7_1?ie=UTF8&psc=1&refRID=XQ430NSTE4QESKBYJZV9


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## seafish (Aug 1, 2012)

lynchknot said:


> I prefer to use ring terminals on my cable ends so I use one like this: https://www.amazon.com/XSCORPION-CB...id=1473899605&sr=1-3&keywords=circuit+breaker or https://www.amazon.com/dp/B01HDX3YXG?psc=1
> 
> #1 best seller: https://www.amazon.com/Bussmann-CB1...7_1?ie=UTF8&psc=1&refRID=XQ430NSTE4QESKBYJZV9


Out of all of those, and for the minimal price difference, I would ONLY go with the last link, the Bussman circuitbreaker....simply because it is manufactured by/for a reputable oem electrical circuit manufacturer.


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## What? (Jun 5, 2008)

Bussman breakers work great. They are waterproof and available in 50, 70, 80, 100, 120, 135, and 150A sizes. JL Audio also offers marine breakers but only up to 80A.
I have not used the cheaper metra breakers but I don't like the AAMP breakers.


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## MACS (Oct 3, 2007)

Blue Sea has nice quality products, but their breakers are pricey. 

The Bussman CB285 series breaker is a bit cheaper. It has stainless hardware just like the Blue Sea. I run Bussman CB285's in my saltwater boat with zero failures. They have 30 amp to 150 amp models.


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## Tremelune (Sep 5, 2012)

If you're worried about corrosion, just hit the terminals with a bit of Fluid Film. It'll stay shiny for many moons.

You can pretty much spray any rust or metal and it'll stay lubed and protected...


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## rxh0272 (Jul 26, 2020)

Matthew Borgardt said:


> A breaker by design is a a resistor designed to heat up and then reset... a large fuse is a better choice than a breaker... Now if you go by a high quality breaker which will cost you a lot of money, that would not be a bad choice...
> Remember the prime reason why we put a fuse or breaker under hood is to protect the power line, with that said you should put in at least twice the rated fusing of your amplifiersup front... because most amplifiers have fuses built in and that will be your protection for your amp.
> 
> Matt Borgardt
> Oncore/Cadence/Logic


ya, this is an old thread. but, why would you put twice the recommended fusing up front?


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## Holmz (Jul 12, 2017)

An airplane, boat, or a 4x4 should probably use breakers.
If one lives in a city then a fuse works just dandy too.


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## drop1 (Jul 26, 2015)

Victor_inox said:


> breakers works just fine.
> Don`t forget to keep power on your car computer unless it`s old.
> many modern cars required constant current. not just for radio but ECU memory.


On a side note. Resetting the ecu can be beneficial sometimes if its intentional and you re teach it good habits...


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## rob feature (Nov 15, 2015)

I thought Victor made it back from Permabanistan there for a minute. Nope, just an old post. Still using fuses if anyone was wondering


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