continuous breaker trip in aft bilge pump

[bigd9116]

Bringing the boat back to southern md in 2 weeks and went to do some work on it to get ready for the trip. The aft breaker trips after the bilge pump runs for 5-10 seconds. I first tried to switch the beaker and switch same result, I the replaced the pump and disconnected all floats same results. The wires are In wire loom and run from the pump into the engine room in the metal wire runs and very hard to trace out. Where do the wires from the panel tie in? I beleive the wires are labeled 40 or 42. Does anyone know a supplier for the same breakers from the international panel? Im guess the wires must be shorted somewhere?

[comodave]

You could test the breaker by moving the pump wiring to another breaker in the panel that has the same rating in amps to see if the different breaker also trips. If it still trips, then you may have a short in the wiring since you have already swapped out the pump and float switch. Although I would expect the breaker to trip faster than 10 seconds if you had a short. So it might be the breaker is going bad and as the current is flowing and it starts to heat up, the breaker then trips. You have done the first step in trouble shooting the problem by replacing the pump and switch, the next easy thing would be to rule out the breaker by jumping the pump to another breaker. If it still trips, then start checking all the connections for corrosion. If there is corrosion in the connections, the voltage you will have a voltage drop across the corrosion so amperage will go up which might be why the breaker is tripping. Good luck.

[P-Dogg]

Yeah, what he said. Breakers do go bad.

While you have the panel open, I'd recommend checking all of the screw terminal connections on everything else on the panel to make sure that they are snug. If you are really ambitious, you can use an IR thermometer to check connections to see if they are all the same temperature before tightening, after tightening, or both. Remember to do this after they have been under load for a while. And keep the thermometer close to the contact or otherwise pay attention to spot size.

When you find the problem, please report back.

Re-reading the original post, is one to presume that everything was working fine before? Could a PO have replaced the pump with a larger one at some point, which exceeded the ampacity of the breaker?

[prowlersfish]

A few questions breaker rating , exact model of the pump .

On the pump black is negative , brown is positive ( brown w/tracer 3/wire pump ) . don't trust the color of the wires on the boat check them with a meter

can you post a photo of the pump & wiring w/float

[Big D]

....Could a PO have replaced the pump with a larger one at some point, which exceeded the ampacity of the breaker?

+1
Not just exceeding breaker spec but wiring too. If a larger pump was added and wiring size is too small as installed by OEM to accommodate a smaller pump, that will cause the same problem. Also consider that you must start with a charged battery; as the source voltage drops, the current increases. Testing the pump with the charger on usually eliminates that problem. Could be anything mentioned before; wiring size or failure, failing breaker, bad connection somewhere, voltage problem, etc.

[prowlersfish]

That one reason I asked about the breaker rating , assuming its the original it would give you a idea of the wiring rating installed by Trojan , I also ask about a photo , as most pump issues I have run into a install issue /wiring at the pump

[bigd9116]

I tried switching the breaker next to it with the same problem, both 10 amps. I do not have any pictures right now of the pump or wiring and the pump is really tough to access without pulling the aft deck up so I'll work with tough accessb to figure it out. The breakers are 10 amp pr11-2-10.00a-xx push button style. I rigged it up to work to get it home with alligator clips to a temporary battery and will work on it in a few weeks, and post back findings. I'm thinking it has to be in the wiring somewhere. I assume all the wires tie in somewhere before going to the panel, anyone know where? the wires are approx. 12-2 in gray insulation and It does not seem like any of them come into the breaker panel I'm thinking they all go somewhere first. But was very limited on time so I was unable to trace them all the way out.