Bilge Pump SHort

[jackheape]

Search the forums but couldn't find a specific thread on this topic. I am getting a lit led light on my bilge pump on the DC main panel. This is even with all of the breakers off, including the main. The DC main breaker trips when I try to turn it on. Battery switch is set to off. Bilge pump is disconnected.
I am guessing a common short to ground in the wiring somewhere? Anyone have any ideas or experienced this before? Thanks

[exMaggieDrum]

This does seem a bit strange. First of all your main breaker may or may not turn off the alarm circuit (LED light) when you turn it off - probably does not. It may or may not go off if you turn your battery switch off IF it was wired directly to the battery or the battery side of the switch. But that means that the bilge switch should be wired that way too.

I am thinking you are saying that the DC main breaker trips when you turn it on, and not the bilge pump switch. If it is the bilge pump manual override then it is a different animal. But if it is the main breaker, then yes you seem to have some kind of major short, which could be from almost anything that the panel powers, not necessarily the bilge pump.

If it were me, I would take the time to trace all the wiring from the panel down to the bilge pump and make a little diagram. Normally the LED would turn on when the bilge pump is activated/powered (and not just that it just has power available - although that is possible). Some people are very anal about knowing that the bilge pump can do its job whether the battery switch is on or not and want to see a light to show that. But normally it would only go on when the pump is activated (whether it pumps or not).

Two ways that happens (if you have a manual override). First is to push/switch the manual override. The light should go on. If you lift the float switch, it should go on. But I would find the power wire from the battery side (found by your tracing wires diagram). If it comes from the panel somewhere, AFTER the main switch then a short in the wiring to the bilge could be shorted. I would trace the wire to the float switch and see if it is shorted any where.

If it is not the bilge pump circuit you could be seeing a "coincidental" problem, i.e. has nothing to do with the bilge pump.

I've attached how bilge pumps with lights that go on when the bilge pump is energized (or the wires going to the bilge pump whether it is connected or not). Note that the light will go on whether the float switch turns it on or the manual switch is turned on. If you have a dead short in either the wire from the manual side of the switch or the auto side of the switch wiring, then it would cause a trip, but it really should blow the fuse first. You should always have a fuse (put one in if you don't). If you don't then it might trip the main breaker but that is a lot of current.

Come back with questions/comments/more description of what you have. Bilge pump circuits are hard to get your head around if you don't work with electrical circuits much.

[M9.9]

Wonder if the pump is obstructed or motor seized? Seems to me either can cause a short.

[jackheape]

Thanks for the advice. Turns out the wiring to the float switch was shorted. I replaced the switch and the pump and everything works fine now!

[exMaggieDrum]

Bilge pump problems are excellent training.

[pcmm]

Note that when you turn off the main battery switch, your bilge pumps should still work. for safety you should not be able to turn off the bilge pump circuit except for the bilge pump switch. This means that the bilge pump should still work even with the main battery switch turned off! this is the same for the VHF radio! they are safety systems and should not be turned off, EVER!