Circuit breakers - can they go bad?

rfcc150

Cadet
Joined
May 27, 2009
Messages
15
I was out yesterday and noticed after a bit that the breakers (no fuses) had popped for the livewell and the bilge. I have seen the livewell pop before and simply reset it. This time however I can't reset either of them.

I had fired up the livewell earlier to keep a fish. I start it up in "manual" mode to get her filled up. When I went to switch to "auto" mode a while later that's when I noticed the popped breaker(s).

This is a new boat (Princecraft SP186 FnP w/4.3 MPI) - 2004 stock but never been in the water until last year - so things are not corroded.

Is it possible that I have a couple of bad breakers? The livewell is 2 amp, the bilge 3 amp. There are no other devices wired into these circuits.

Thanks in advance
 

sparticus

Petty Officer 3rd Class
Joined
May 31, 2007
Messages
92
Re: Circuit breakers - can they go bad?

Yes its possible to have a bad circuit breaker. I work in the aerospace field and we find them bad on a regular basis. Typically when they go bad they "pop" sooner than they should. Its an inconvience but the alternative is much worse!
 

HappierWet

Master Chief Petty Officer
Joined
Sep 11, 2008
Messages
839
Re: Circuit breakers - can they go bad?

Maybe there was another problem, and ignoring it by only resetting the breakers made it worse. Yes, do go bad with use and occasionally you'll get a bad one from new. I'm only suggesting some trouble shooting may be in order before spending money you may need elsewhere.:cool:
 

slia67

Petty Officer 1st Class
Joined
Jul 11, 2007
Messages
272
Re: Circuit breakers - can they go bad?

The best way to tell if it's a bad breaker, or a true problem, is to check the current draw on the circuit while the pumps are running. One of your pumps may be getting hot after being used for some time and drawing too many amps.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: Circuit breakers - can they go bad?

Each time a circuit breaker trips, it derates a bit (loses a bit of its current handling ability). A 10A breaker for example that has tripped numerous times may begin tripping at 9A, then 8A etc. So if a device would normally draw 8A the breaker would continuously trip. Since this is a new boat, then I suspect there are some wiring issues or breaker size issues.
 

jw228w

Recruit
Joined
Aug 3, 2008
Messages
4
Re: Circuit breakers - can they go bad?

how does one check a circuit breaker? i have a voltmeter,is there a web site that would demonstrate this?mine for my livewell pump has also started to trip on a frequent basis.
thanks john
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: Circuit breakers - can they go bad?

If the breaker doesn't pop when filling the livewell, but does AFTER you switch to the "TIMER" mode, that says the timer may be the issue. Both of those breakers seem small and have now derated to the point where they simply cannot handle the current the motors are drawing. You can't check the breaker separately with a volt meter but if your voltmeter also has a CURRENT (amps) measuring capability you simply disconnect one wire from the breaker and insert the meter between the end of that wire and the terminal it was disconnected from. WARNING: Your meter must be capable of reading at least 5 amps and you need to only flick the switch on and off QUICKLY to get a reading. DO NOT MISUNDERSTAND a label on the meter that says 10 mA (milliamps which is .001 amps not 10 amps). If the readings you get are higher than the rating on the breaker, the breaker is too small or there is an issue with the pumps. Current draw for the pumps is generally stamped on the pump. Otherwise Google the make and model of the pump and get the current specs. If current draw spec is 5 amps and you see it is drawing 7 amps, the pump is an issue.
 

rwidman

Lieutenant
Joined
May 27, 2004
Messages
1,396
Re: Circuit breakers - can they go bad?

how does one check a circuit breaker? i have a voltmeter,is there a web site that would demonstrate this?mine for my livewell pump has also started to trip on a frequent basis.
thanks john

It's more likely a problem with the pump than a defective circuit breaker. Check to see that it spins freely and there is no debris stuck in it or an obstruction in the plumbing.

One of the easiest and least technical ways to check a suspected defective circuit breaker is to replace it with one you know is not defective. There is a very small chance that a new one is defective. A very small chance.

A more technical method is to measure the current flowing through the circuit breaker. If it's a five amp breaker and trips at three amps, it's defective.
 

RicMic

Chief Petty Officer
Joined
May 14, 2010
Messages
431
Re: Circuit breakers - can they go bad?

Its extremely unlikely that two nearly new circuit breakers went bad at the same time. Are you saying that the "circuit breakers" are two and three amp OR the pump motors are two and three amp? Also being "new", dosn't mean there is no corrosion. I just rewired a "new" 2006 boat that had never been in the water and much of the wiring was oxidized black way inside of the insulation.
 
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