Electrical Q #1 from a Greenie

[tartan30cirrus]

My bilge pump has 12/3 cable...a white, a green, and a black. It was spliced with a 16/2 cable that goes to the bilge pump switch (a 2 way) in cockpit. I accidentally pulled the splices apart when i was yanking what I thought was another wire. I resnaked the 16/2 bilge pump cable which goes from the switch in the cockpit to the 12/3 cable down near the bilge. I connected the red w/white/green w/ black and the bilge pump worked when I put the switch in the automatic position and did not work when I pushed the switch the other way, the manual posiiton. This is the total opposite of normal operation. So I connected the wires opposite to the way I mentioned above, same strasnge result. The pump should not turn on in the auto position unless there is water/should turn on when I push the switch in the other direction. I am getting backwards results. Hope this was clear. What is going on? And the 3rd wire coming from the bilge pump is black. Why are there 3 wires?

Cheers,
Clint
T30 #388 Cirrus

[Tim]

Bilge pumps with float switches use three wires. I don't have a wiring schematic handy here, but one of the wires is the ground (usually black in DC), one is the power supply (+), and the third is for the automatic switch. The white/green/black cable you have is technically AC cable (based on its colors), though it works just fine for DC as well.

The pump itself probably has two brown wires and a black. The black is the ground, one of the browns is the power (+), and the other brown is for the automatic switch. This is how I recall it.

You need to trace out the colors in your 3-conductor cable and see where they connect at the pump end. Be sure you are connecting the 2-wire conductor from your cockpit switch to the correct wires of the pump. I think you might be connecting a wire from the float switch directly to a power lead, which could cause the condition you are describing. It's hard to say for sure since I don't know exactly what you have there.

[Figment]

Does the pump itself have two wires or three?
I've only ever seen a few pumps that came out of the box with three wires, and there's always a bit of head-scratching to mate the three-wire system to the two-wire pump. (I've burned through a LOT of bilge pumps over the years)

It's sometimes easier if you think of it as a simple two-wire job, and then cobble-in the third wire via the float switch. Here's my rough memory of how it goes....

Ground (black wire) is easy. ground to ground.
The brown wire on the pump is the hot wire. Connect this to the "manual" post on the 3position switch with the white wire of the cable.
Now the green wire is for the automatic float switch. Wire from the automatic post on the 3position switch to the float. Then wire from the float to the brown wire of the pump.... the one that's already connected to the white wire.

So when the job is done, the black wire from the pump is connected to the black wire of the cable, and the brown wire of the pump is connected to BOTH the white and green wires. This, I think, is what you don't have at the moment. You only have one wire connected to the pump's brown wire, right?

My policy on bilgepump wiring is to solder the connection, swab with "liquid electrical tape" and then heat-shrink, but that's just me.

I think Rule or someone has the wiring diagram on their website.
Acutally, West Marine may have it on their website or even in the bilgepump section of their huge catalog.

Edited in italics above to answer the question more directly. I babble. My apologies.

[tartan30cirrus]

Thanks for help guys. I am still confused, but let me tell you what i have and hopefully you can help...

I have a breaker, a 3 way switch (manual-middle/off-automatic posiitons), and the pump in the circuit. The current set up is (dashes are connections...

Starting @ PUMP
brown wire --------- white wire ------- white wire from breaker
brown/white stripes wire ---------green wire ------- no connection
black wire --------black wire ---------black wire from breaker

Starting @ 3 way switch
black wire from manual post ----------- ?????
white wire from middle post ------------???????
no wire on automatic post
soooo.........
I do not know which wires from the pump/breaker to connnect these to.

Currently if I turn the breaker on the pump turns on. When I connect the switch wires to the white or green the pump runs only when I throw the switch to the auto position.

Thanks!!!!!
Cheers,
Clint
T30 #388 Cirrus

[Tim]

It's been a long while since I actually looked at my pump wiring, and Figment is right in that there are only two wires from the pump--brown and black. My memory stands corrected, and I regret the bad info.

With an automatic float switch, though, there are two additional wires from the switch itself, which get connected with other wires from the pump.

Here is a wiring schematic for a typical 2-wire bilge pump and 2-wire automatic float switch. This shows the wires from the pump and float as well as their connections at a 3-way toggle switch (auto-off-manual). Forget what you have now and wire the system according to this diagram, and it should work just fine. (According to your description, your pump is simply wired through the breaker at the moment, and not properly through the toggle switch first and then to the breaker.)

Note that the terminals on the toggle switch are not labeled in this drawing. The upper terminal here (directly below where it reads "Toggle Switch") is the "manual" position, whereas the lower terminal shown (directly above where it reads "Red Lite") is the "auto" position.



The brown wire from the pump (+) is spliced in with one of the black wires from the float switch; the resulting single wire then connects to the "auto" side of the 3-way panel switch. You can make the splice with a step-down inline butt connector or some such.

The black wire from the pump goes to ground (negative distribution).

The second black wire from the float switch runs to the manual side of the panel switch.

The wires from your circuit breaker to the 3-way bilge pump switch are represented at the switch by the "+ to battery" wire and the "ground" in the schematic .

The bilge pump, located in a known wet area, should be carefully wired to ensure watertight connections. Also try and route the wires up immediately so that they will remain dry. Secure them under the sole or elsewhere to keep them away from the usual amount of bilge water.

[Figment]

So your pump has three wires..... Does it have its own integral float switch? You didn't mention a stand-alone float, so I assume that this is the case.

holdonasec... breaker? doesn't your 3way switch have an integral fuse? Anyway, I digress.

Breaker/fuse should be between battery and switch. Shouldn't have anything to do with the actual pump wiring.

Power from battery to breaker. Power from breaker to 3way switch, I think via the middle post, though this may vary from switch to switch. I'm writing all of this on the assumption of the ubiquitous Rule 3way.


I assume the brown/white stripes wire to be the automatic float wire for the pump, so it's correct to connect it to the green wire of the cable. Next step: connect this green wire to the automatic terminal on the 3way switch.
Then the white from the pump to the manual post on the switch.
Black from the pump should be the pump's ground. Connect this to your primary ground terminal via the fewest connections possible.

Because power all runs in one direction and the ground doesn't (shouldn't, IMHO) return to the switch panel, bilgepump wiring doesn't lend itself well to premanufactured black and white cable pairs. As a result, everyone makes their own compromise and I really doubt we'll ever see two boats with the same bilgepump wiring scheme.

Tim, where on earth did you dredge up that diagram? I spent a good five minutes of fruitless googling before I surrendered.

[Tim]

Tim, where on earth did you dredge up that diagram? I spent a good five minutes of fruitless googling before I surrendered.

Ah, I save all manuals. This is from the instruction manual for my own Rule pump and switch.

[tartan30cirrus]

Thank Figment and Tim for ideas...still a bit confused but closer...anyway I fiddled around and got it to work like it did before...but I need to pour some water in the bilge (once the average low is above freezing) and test to see that the automatic setting works!

Cheers,
Clint Chase
T30 #388 Cirrus