Circuit breaker

[dickboxers]

I just doubled my alternator from a 55 to a 110amp. First time on lake last weekend the circuit breaker tripped. Then went the rest of the day without a problem. Fluke or do i need to change something. It has a 50amp breaker. I see that there is a 60amp breaker, but i don't want to end up causing another issue if the breaker doesnt trip and messes something else up. What size do most of you have in your boats?

[wotan2525]

Look at your wiring and figure out if the charging circuit is going through that breaker. You don't want your alt. putting 110amps through it and causing it to trip every time you rev the engine. I bypassed my circuit breaker and then added a 200amp master fuse on mine. Everything else is also fused independently.

[haugy]

Look at your wiring and figure out if the charging circuit is going through that breaker. You don't want your alt. putting 110amps through it and causing it to trip every time you rev the engine. I bypassed my circuit breaker and then added a 200amp master fuse on mine. Everything else is also fused independently.

Wotan, did you just run your main cable from your alternator to your battery/perko with a 200amp fuse? I'm looking at the big amp 1-wire GM style alternator and that would be my plan. Bypass everything and straight line into the batteries.

[wotan2525]

Yep! I'll have to double check but I believe I have 00-gauge -> fuse -> starter terminal -> 1-wire alt.

There's a smaller wire from the starter terminal -> engine wiring harness/coil/etc.

I actually have a 150amp circuit breaker kicking around my junk drawer. Never installed it because I decided the fuse was ultimately easier.

[Wylietunes]

1st, but unrelated to the breaker trip, did you also upgrade the main alternator cable gauge?

Next, if you did upgrade the cable, did you terminate it to the same spot as the original?

Next, what is that breaker for? In other words, where does it obtain its B+ from and what boat circuits are it feeding?

Heres some info about the alternator and circuit protection such as fuses and or breakers. Fuses and breakers are intended to protect the circuit (wiring) between the battery source, whether its directly off a battery or a fuse block, and device drawing the current. Fuses and breakers are not there to protect the voltage source. This would be like a dam stopping the river's flow from filling the lake if that makes sense. The dame is there to control the flow of water out of the lake and down the river. Flwo gets too high and we close the dam.

So, logic has it that the breaker tripped due to the load pulling on it.

Alternators are regulated, so their out put is based on demand. In theory, our 110A alt has the potential to put out 110A, but I doubt you will ever see anything over 75% of that. So in no way shape or form, did you go from 5%A to 110A, you just upped the potential. If nothing has changed recently but the alternator upgrade, then the output of the new 110A is exactly the same as what the old one was. As stated, its output is purely based on demand.

So, do not up the size of the breaker as it may exceed the capacity of of the cabling. if that happens, the cabling become the week link and melts down in an over-current scenario. Determine what circuits that breaker feeds and see if extra loads have been placed on that circuit over the years. If so, the separate those new loads on to a new BUSS feed that can carry them. This gets the OEM breaker back to feeding what it was intended to.

It is possible to have a breaker going bad, buts hard to diagnose, especially if there are extra loads on that circuit.

[dickboxers]

Thanks for the knowledge Michael. I will look at the wiring, but the guy who owned boat before me and restored it was an electrician so i would trust his wiring before mine. The only thing i have added was 4 tower speakers (already had enough amps to run) and i changed alternator. I have had the breaker trip before so it might just be the breaker.

[haugy]

Yep! I'll have to double check but I believe I have 00-gauge -> fuse -> starter terminal -> 1-wire alt.
There's a smaller wire from the starter terminal -> engine wiring harness/coil/etc.
I actually have a 150amp circuit breaker kicking around my junk drawer. Never installed it because I decided the fuse was ultimately easier.

Wait a second. You're saying there that you are running from the alternator, to the circuit breaker, to the fuse, and then to the battery all on 0/0 gauge? I thought with those 1 wire alternators I could completely by pass the circuit breaker (since it's a 160 amp alt) and run a main line (fused) into my perko switch for the batteries. Which I also need to make sure my perko can handle that much power.

The small wire should be wired up right where the positive meets the starter, and that powers up the coil/ign/etc......right? Therefore the alternator just needs to supply the batteries. And from the perko you would have two lines coming from the perko (one alt, one to the starter).

Right? I always suck at electrical.

[wotan2525]

Wait a second. You're saying there that you are running from the alternator, to the circuit breaker, to the fuse, and then to the battery all on 0/0 gauge? I thought with those 1 wire alternators I could completely by pass the circuit breaker (since it's a 160 amp alt) and run a main line (fused) into my perko switch for the batteries. Which I also need to make sure my perko can handle that much power.

The small wire should be wired up right where the positive meets the starter, and that powers up the coil/ign/etc......right? Therefore the alternator just needs to supply the batteries. And from the perko you would have two lines coming from the perko (one alt, one to the starter).

Right? I always suck at electrical.

No circuit breaker. And you're describing the same basic circuit.

The +12v from the perko/battery is unswitched so it doesn't make a difference if it goes batt->alt->starter or batt->starter->alt or alt<-batt->start (like yours is.)

Just picture that your +12v from the battery is all hot, all the time.... see how it doesn't matter where it connects or overlaps?

[haugy]

I know they are hot all the time, but I'm wanting to run a shorter line to the batteries. Versus running from the alt, to the starter, then back to the battery. That's how mine is now.

I'm not sure if I'm explaining it right, but I've got it. I'll be running a hot run from the alternator to the perko line out. And a hot run from that same perko line out to the starter/ignition system. My only thought is that going to cause interference issues and fry something?