Author Topic: Wiring the auto bilge pump  (Read 30208 times)

Offline walknbob

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Wiring the auto bilge pump
« on: April 23, 2008, 03:14:40 PM »
I am wiring for my auto bilge pump. It's a Rule 500 gpm auto with (internal not add-on float).

It has a black, a brown, and a brown with white stripe wire. As I understand it the brn/stripe wire would be the hot/pos wire. The black is ground. The solid brown is the "auto" wire. But in reality whether I were to switch the pump on or not, being automatic, it would run anytime there is enough water to float the pump (about an inch or so). So if it was switched off it would pump when needed. What is the advantage of the switch unless you wanted it to never come on, then what is the point of having an auto?
I plan to run a #10 pos wire back from the house battery (17') with an inline 2.5 amp fuse near the battery (which means it will be protected from the weather). I also plan on installing an 1100 gph pump with switch connected to the pos & neg buses located at the transom. These would be dead (except for the common ground) when the battery switch was turned to off.

Oh yeah so my question is - A. does the auto pump actually need a switch or can it just be direct wired without one? B. If no switch is needed do I just use the one solid brown wire? C. If it does need a switch does the striped wire go to the switch, if so how do you connect the solid brown wire?
WalknBob aka Bob Southwick - Depoe Bay OR

Offline kchace

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Re: Wiring the auto bilge pump
« Reply #1 on: April 24, 2008, 06:07:40 AM »

  There are some people who wire up the auto side of a pump to a switch. In my mind that defeats the whole purpose which I think is what you're saying too. My auto pumps are both wired direct to the batteries (one each) and cannot be 'turned off' because in my mind, an auto pump should be just that - something that can automatically take care of water even when you're not using the boat. Just make sure to have an inline fuse near the battery. I used the posts on the back of the battery switch for these connections.

  The purpose of the 'manual' wire is to allow you to get rid of nuisance water that isn't high enough to cause the auto switch to go on and also in case the auto switch fails.

  From your description, it sounds like you have the Rule-Mate 500.

  Assuming you want the automatic feature available all the time, you would wire as follows: The solid brown wire goes to the automatic side of the pump. As such, it should be directly connected to 12V. The brown with white stripe is the manual switched power and should go to a fused switch - then to 12V. Black goes to gnd.

  The fuse spec for this pump is 2.5 amps. As such, your 10ga wire is way overkill. It won't hurt anything if you happen to have it laying around, but 14ga is plenty, even for that run.

  You may also want to refer to my schematic which shows how I wired my pumps.

https://fishyfish.com/boards/index.php?topic=93.15

  Ken
Ken Chace
The Lucky C
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Offline walknbob

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Re: Wiring the auto bilge pump
« Reply #2 on: April 24, 2008, 09:09:50 AM »

The fuse spec for this pump is 2.5 amps. As such, your 10ga wire is way overkill. It won't hurt anything if you happen to have it laying around, but 14ga is plenty, even for that run.

  You may also want to refer to my schematic which shows how I wired my pumps.

https://fishyfish.com/boards/index.php?topic=93.15

Thanks Ken

It is a Rule-Mate 500. One reason for #10 wire is I dont think I can find a connection with a hole large enough to go over the battery screw down post on a wire smaller than that. And over long runs I just feel like too big is better than too small.

« Last Edit: April 24, 2008, 09:21:51 AM by walknbob »
WalknBob aka Bob Southwick - Depoe Bay OR

Offline kchace

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Re: Wiring the auto bilge pump
« Reply #3 on: April 24, 2008, 09:47:04 AM »

The fuse spec for this pump is 2.5 amps. As such, your 10ga wire is way overkill. It won't hurt anything if you happen to have it laying around, but 14ga is plenty, even for that run.

  You may also want to refer to my schematic which shows how I wired my pumps.

https://fishyfish.com/boards/index.php?topic=93.15

Thanks Ken

It is a Rule-Mate 500. One reason for #10 wire is I dont think I can find a connection with a hole large enough to go over the battery screw down post on a wire smaller than that. And over long runs I just feel like too big is better than too small.



  Well, the #10 wire is certainly better than too small. The connectors for say #14 over a 3/8 stud are available, but they're certainly not as easy to find as the bigger stuff. Keep in mind that the negative battery post is usually 5/16 and only the positive post is 3/8.

  Ken
Ken Chace
The Lucky C
25' Jumbo