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Email This Page to a FriendPreview: How to Wire a Bilge Pump – Marine Electrical Systems
July 17, 2012
Figuring out how to wire a bilge pump to your battery doesn't have to be a chore to put off any longer. Follow Don Eley as he takes us step by step through the process and get some pretty handy tips along the way.
– Today we’re gonna talk a little bit about installing a automatic bilge pump in a little Herreshoff 12 1/2. And this system is about as simple as you can get. All we’re gonna have is a pump and a battery. This pump happens to be the pretty standard pump that you’ll find for a submergeable bilge pump. It has a little impeller here. It’s a centrifugal style pump, and then there’s a float switch here that’s also part of the pump. So when this is installed, that float switch moves up when you have enough water in the bilge, it turns the pump on and then shuts the pump off when it pumps all the water out. It’s just gonna sit down here in the bottom of the bilge. The base is already attached. And it just snaps into place there. This bilge pump is designed to be mounted fore and aft, with the output facing aft, so that’s the way this is designed. And that’s the way we’re gonna install it. We’ve got a hose here that takes a loop up near the deck and then it goes overboard. And we’ll attach it with this stainless steel hose clamp. One of the things about a stainless steel hose clamp is you need to make sure that both the band is stainless and the screw itself is stainless. The typical one you’ll get from an automotive store will be steel and it’ll look nice and shiny but it’s not all stainless and you’ll have lots of trouble with that in the future. All right, so we’re gonna pull the pump out and then install this hose because it’s pretty tight here with the floor. And there’s the pump comes out. And we’ll put this clamp on. Slides on there like this. And then the whole thing can snap back into place. Good to go there. There it is. And then we can tighten it. Close the clamp up. Close the clamp tight. I like to have it so obviously the screw is accessible. I’ll get a couple clamps on here later. And the pump is physically installed at that point. Now what we’re gonna do with the wires here, notice there’s three wires here. There’s a black, a brown, and then a third wire here, this is the brown one with a white stripe, is designed for the manual switch so that you could actually turn the pump on manually. In this particular case, we’re not gonna be set up that way. We’re just gonna leave it in the fully automatic mode. And that’ll then allow us to just hook this up and leave it be and we won’t have to worry about it. So I’ve dead-ended the one wire here and now I’m left with just the black and the brown. The black happens to be the negative, and the brown is the positive. And I’ve also set these up so they’re polarized. You’ll notice that they’re opposite each other so that when you hook this pump up, you can’t hook it up backwards. We’ve got a small, what’s called an AGM battery, Absorbent Glass Mat. And this would be, all we’re gonna be running on this particular boat is the bilge pump. And the neat thing about the Absorbent Glass Mat battery is that it’s totally sealed and we can actually mount it, if we wanted to, we could mount it sideways, or we could mount it upside-down, and nothing will ever leak. So this is a really great battery to have for, certainly on a boat where you don’t have to be dealing with maintenance of the battery. We have a battery bracket arrangement down in here. It’s designed to keep the battery from moving side to side or fore and aft, and then we have this strap here that’s set up so that we can tie the battery in place so it can’t even move up and down. So that’s gonna keep the battery firmly in place. So it sets down in there like that. And then we have this little strap that runs under the bracket, over the battery, and holds that battery in place. All right. So this is gonna be strapped down and tight. And it won’t move in any direction at that point. So the next thing we want to do is talk about hooking the bilge pump up to the battery. The newer convention to battery wire coloring is red for positive and yellow for the negative. On the bilge pump itself, you notice that we had color coding that came from the bilge pump manufacturer. Black was the negative and brown was the positive. So a little confusion there in terms of color coding, but that’s the standard for bilge pump. But the standard for coming off of a wire, or off a battery would be the red and the yellow, so that’s what we’re gonna go to. On the red side here, this is the positive side, we’re required to fuse the positive side of the wire that’s coming off the battery. In this particular case, the pump itself tells us the fuse size that we should use. So if we look at the pump, the pump on the top of the pump is actually telling us that we need to fuse this particular pump at three Amps. And what that’s doing is that in case the pump was ever to get in a situation that we call a locked rotor, this is where the piece of wood or something like that gets stuck in the impeller of the pump and the pump gets stuck in the on position. We want to be able to protect that pump by putting a fuse in place that will protect it and the fuse will blow up before the pump actually destroys itself or catches on fire. So in this particular case, the pump manufacturer’s telling us to use a three Amp fuse. So that’s what we have in here, is a three Amp fuse, meaning that if the current exceeds three Amps, it will then blow and the pump will actually shut off, but we won’t do any damage to the wiring or to the pump. So that’s in series with our positive lead. This is gonna go to our positive post of our battery. And this is the yellow is gonna go to our negative post. And what I’ve done on the pump already, as I mentioned, was we’ve got a male and female spade connection here and we’re gonna make the same up on our battery end so that if we ever want to disconnect the pump for whatever reason, it’s a quick disconnect. We have several connectors here and they come in lots of different colors. And the color coding actually has to do with the wire size. In our particular case, we’re gonna be using 16 gauge wire and so what we’re gonna be using is blue connectors. So we have these blue connectors here and these are actually what we call heat-shrink style connectors, so actually after we crimp the connection, then we’ll be able to heat the end here, it’ll shrink, and we wind up with a fitting like we see right here that’s sealed completely all the way around. And that’s nice to have, especially in a bilge operation. What we’re gonna do now is we’re gonna strip the ends of the wire off, the insulation off, so that we can put the wire up inside the connector and then crimp that wire at the connector itself. Okay, a couple ways we can do that. We’ve got lots of different tools here for stripping the wire off. This is a handy one here. It actually has the gauges marked out across the holes there and it kind of works neat. This comes down first and holds the wire. And then as you pull on it, it will strip the wire end off. We’ll take a look at that. I guess we can do this one that way right now. So we’re gonna put this into the 16 gauge slot. That’s about the amount that we want to have stripped off. And do this. There, that just strips the end of the wire off. And so now the end of the wire is exposed, we’ll be able to put it up inside the crimp connector and then crimp that. Of course, we want to make sure we’ve got the right one going to the right lead on the pump. So in this particular case, the red is going to the brown. So we’re actually gonna want the female crimp to the red so that when we put these two together then we’ve got our wire in the right direction. Okay. So, there’s the connector in place. And there’s a couple of different crimpers we can use. I think this is the standard one that most people are familiar with. You can find this at an automotive store. And notice at the end here there’s red, blue, and yellow indicators. And those indicators are for the size of the connector that we’re using. So the terminal end. So in this particular case we’re using a blue terminal end so we would use this particular set of jaws. Okay so here’s another crimping tool we can use, a little heavier-duty than the last one that I just showed you. But notice it’s marked in the same fashion. So we’ve got the red, the blue, and the yellow. And that’s an indicator of the terminal that we’re going to crimp. So in this case, we’re going to be crimping the blue, which is the center one there. We’re gonna set this into place here. Make sure the wire is pushed all the way into place. And then it releases itself when the crimp is done. And now that’s a nice, tight crimp. We can also use this tool. This is a handy little tool for stripping, a little different than the last one that I showed you. This one’s kind of neat. You just put the wire in place to the length that you want to strip it, pull the handle down, and you’re done. And that one you don’t need to determine what wire gauge it is. That one will strip anything from 20 gauge all the way up to about a 10 gauge wire. So that’s kind of a handy tool to have also. So any of these tools work well. So here’s the last one. This is gonna be on our negative side, that’s the yellow in this particular case. And we’re gonna go ahead and slide it up there. This time just to show you, we’ll use this crimper. But again, even though the wire’s yellow, the terminal end is blue. So we’re gonna use the blue jaws in this particular case. Now this one doesn’t, this one doesn’t release itself automatically. You’ve gotta just push the wire in there. We’re gonna crimp that down. And then release it. So both of those do a great job. You can see where the crimp is right here in the middle of the, of where the wire is up inside the barrel there, the terminal. All right, so now what we’re gonna do is we’re gonna use a heat gun and we’re just gonna heat up the collar here and once the collar’s hot, you’ll see that it shrinks tight around, tight around the wire, and we’ve got a nice watertight seal at that end anyways of the connection. So let’s make sure we have things correct. The black on the pump is the negative, which is our yellow coming off the battery, so those will slide together. And then the brown is the positive on the battery side, and those will slide together. Now, this is not a watertight connection. We’re gonna hold it up out of the bilge. You could put a little silicone on that also if you wanted to seal those up good and tight. But this allows us to be able to change the pump out if we need to, without redoing the whole battery wiring again. All right, so this is gonna, we’ll tie this up in the bilge here when we’re finished. And we’re gonna bring the positive and the negative leads up to the battery. Positive again is the red. It’s the one with the fuse in it. And so we’ll go ahead and connect the positive here. And the negative, the yellow, is gonna come over to the negative side. And I’m gonna tighten our connections up here. You want to make sure you don’t touch the two terminals together with your wrench. That’s a disaster. But now I’ve got access to my fuse right here if I ever need it. This is all gonna stay up high out of the bilge. And at this point now we should be able to, on this particular pump it actually has a little manual override that you can turn the pump on and off. And there it is. It’s on. And since the bilge is empty, it shuts off automatically. All right, so all we’ve got left now is to tie up the wires up out of the bilge. And we’ve got a little terminal block here that allows us to run a wire tie through it, which is pretty handy. That ties all the wires up out of the bilge. We’ve got our connections that are easy access, we’ve got our fuse that’s easy access, and our pump. And there you have it. That’s a simple installation anyways of a bilge pump in a little 12.5.