Switch in Off Position Causes Breaker to Trip

[Patrick_DeepPlaya]

I have a switch I'm putting in, actually putting back in which when in the off position causes the breaker panel to trip and I'm completely stumped.

I have tried two switches, with both appear to be Cole Herse brand pull switches. They have two single screw terminals on the back. They are not labeled pos or neg on either terminal.

Background on the wiring:
P.O. was into soldering and taping over inline splices and other (IMHO) less reliable connections. I have been going around and cleaning these up by putting in terminal blocks and heatshrink glue ring terminals on the ends of the connections.

THis circuit in particular is my water pressure system. In this circuit there are two pumps oner for my fresh water and it on\off when the breaker is on\off. The second pump is my anchor washdown pump, and it is intended to be on\off based on the switch.

The feed wire from the breakers goes to a terminal block.
From this block the fresh water pump is connected. Another 30' run of Ancor 12awg marine grade\tinned wire runs to the bow. Here, I wired the pos wire from the feed wire and the pos wire from the pump to one terminal on the switch and the neg wires from the feed wire and pump to the other terminal.

If I place the anchor washdown switch in the ON position and turn on the breaker the anchor washdown pump runs fine and I can also run the fresh water pump simultaneously.

If I place the anchor washdown switch in the OFF position and turn the breaker on, the DC amp indicator spikes up and then the breaker trips, the pump does not run.

If I remove the switch and just let the feed line to the anchor washdown sit unconnected the fresh water pumps works fine.

Thanks for the help, I'm sure this is something obvious to more experienced electrically skilled folks.

Thanks,
-p

[hellosailor]

" Here, I wired the pos wire from the feed wire and the pos wire from the pump to one terminal on the switch and the neg wires from the feed wire and pump to the other terminal."
There's the problem. You are supposed to run the positive supply from the breaker to one terminal on the switch, and then connect the positive lead from the pump to the other terminal on the switch.
The negative leads go to a GROUND BUS, not to the same switch. (Unless you are talking about double-pole switches that have four connections and make/break both sides of the circuit at once, which would be most unusual in a DC circuit.)

[Pblais]

Replacing the soldered and taped splices - very good. Using heatshrink butt connectors and using heat shrink ring connectors also - very good. This has nothing to do with the problem you have. Reusing the same wire may in fact not change aything what so ever as much as the better connectors are - better.

It sounds like you have a system that was wired creatively (in a bad way) and are trying to do things right only to a point. You can still have a poor system. Running sections direct from the panel so you can split them in other places gets complicated and prone to mistakes and a lot of extra connections. Often done for lighting that use low amp loads but never done on anything that uses more amps.

The other reason it's commonly done is because the PO was lazy and cheap and commonly both. They may have built a fire trap for your demise just to save some wire. You are telling me this may be in a lot of other places on the boat!

Wire size calculations become complex as well when splitting things. This one sounds over the edge of too many feet in too little wire. You want to stay under a 2% voltage drop. The amp load vs the distance will give you the needed wire size. I would do that for all runs and would not accept that anything not original was done right and anything original that was extended is clearly bad.

The length includes the out plus the back! This number 12 wire looks really undersized to me. Two pumps on the same breaker sounds like it's really a bad set of wire. You start screwing up with 10 DC amps and you can make fire really easy. I say 10 amps assuming you have really whimpy pumps. The real load could be 30 amps and is why your breaker blows. This isn't flashlights. This much power could actually hurt you.

80% of all boat fires of any cause are from electrical system failures. I really think you need some help sorting this out and I wouldn't go any farther without going over the whole electrical system. Make some drawings and talk to a pro. Make a new plan for all the work. It takes a long time to wire a boat properly after it's built it's why some of this stuff happens.

[David M]

Your larger loads, like pumps, each need their own breaker. It sounds like you may need a larger DC panel that has more breakers that can provide adequate circuit protection for all of your loads.

[Tellie]

Originally Posted by Patrick_Seattle

I have a switch I'm putting in, actually putting back in which when in the off position causes the breaker panel to trip and I'm completely stumped.

I have tried two switches, with both appear to be Cole Herse brand pull switches. They have two single screw terminals on the back. They are not labeled pos or neg on either terminal.

Background on the wiring:
P.O. was into soldering and taping over inline splices and other (IMHO) less reliable connections. I have been going around and cleaning these up by putting in terminal blocks and heatshrink glue ring terminals on the ends of the connections.

THis circuit in particular is my water pressure system. In this circuit there are two pumps oner for my fresh water and it on\off when the breaker is on\off. The second pump is my anchor washdown pump, and it is intended to be on\off based on the switch.

The feed wire from the breakers goes to a terminal block.
From this block the fresh water pump is connected. Another 30' run of Ancor 12awg marine grade\tinned wire runs to the bow. Here, I wired the pos wire from the feed wire and the pos wire from the pump to one terminal on the switch and the neg wires from the feed wire and pump to the other terminal.

If I place the anchor washdown switch in the ON position and turn on the breaker the anchor washdown pump runs fine and I can also run the fresh water pump simultaneously.

If I place the anchor washdown switch in the OFF position and turn the breaker on, the DC amp indicator spikes up and then the breaker trips, the pump does not run.

If I remove the switch and just let the feed line to the anchor washdown sit unconnected the fresh water pumps works fine.

Thanks for the help, I'm sure this is something obvious to more experienced electrically skilled folks.

Thanks,
-p

While I agree with the others, you haven't given enough clear information. It sounds like it just isn't wired correctly. Pics would help. But you don't mention size of breakers, what type of terminal block is used. Is the 30' run measured from the DC source and back or is it really 60'? Again pics would help but from what you are describing and how you are describing it, I would suggest professional help would be a wise investment to start.

[Patrick_DeepPlaya]

Originally Posted by hellosailor

" Here, I wired the pos wire from the feed wire and the pos wire from the pump to one terminal on the switch and the neg wires from the feed wire and pump to the other terminal."
There's the problem. You are supposed to run the positive supply from the breaker to one terminal on the switch, and then connect the positive lead from the pump to the other terminal on the switch.
The negative leads go to a GROUND BUS, not to the same switch. (Unless you are talking about double-pole switches that have four connections and make/break both sides of the circuit at once, which would be most unusual in a DC circuit.)

OK, now I'm just plain embarassed, I had no documentation with these switch and I took it out last year (without documenting how it was wired) so I was kind of flying blind, but now that I see your description I know what I did make no sense at all. I basically put in a switch that would short out the circuit... DUH !!!

I wired it properly as you describe and we're back to full functionality.

To the longer replies, thanks for the tips.

--Embarrased -- ;-)

[GordMay]

Standard Rocker Switch Circuit Diagrams:
➥ http://www.carlingtech.com/pdf/v_ser...ircuitdiag.pdf

Bilge Pump Wiring Diagrams:

➥ http://www.cruisersforum.com/gallery...r&imageuser=79

➥ http://www.cruisersforum.com/gallery...r&imageuser=79