RV Lifestyle & Repair Editors

How to Install an Automatic RV Transfer Switch

RV Lifestyle & Repair Editors
Duration:   20  mins

Description

The shoreline cord is what gets connected to your RV bringing in power to your distribution center. Older models have a J Box, which has a receptacle coming from the generator and another that goes to the distribution center. This requires you to have to go outside and plug in the generator every time you want to use it.

Newer models come with an automatic RV transfer switch already installed, eliminating the need to have to manually unplug from shore power and plug in the generator. It is possible to upgrade older models to an automatic 30-Amp RV transfer switch, which will put everything you need in one single box.

Before installing a RV transfer switch you will want to make sure that all power sources to the RV are disconnected, including generators, shore lines and batteries. Remove the 4×4 boxes and disconnect any wires that are connected to the older style units.

The automatic RV transfer switch has decals where everything gets hooked up. It is important to follow these guidelines to ensure nothing gets hooked up incorrectly. Look at the box and the placement to determine which punch outs to remove from the box so the wires can be run through it.

Connect the grounding wires first, followed by the shore power lines, generator wires and load center wires. Be careful not to have the screw go into the wire insulation. This can cause a poor connection and will generate heat, which could cause a fire.

Once done make sure all wires are connected correctly and tightly. The plug it in and verify that there is power coming in from the shore power and into the load center. The next test is when the generator is started; the shore power should automatically shut off.

If you are still unsure of how to upgrade to a 30-Amp RV transfer switch, contact a certified electrician to help work on your RV.

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The shoreline cord from your RV is gonna bring power into the distribution center. This is an older model here, it's got a J box, it's called. Here we've got the receptacle that comes from the generator. This box here takes it up to the distribution center. With this one, if I want to use the generator, I have to physically plug this in every time.

The newer ones now come with an automatic transfer switch. Now, you'll even see this on some of the less expensive trailers out in the market. So what we want to do is we want to upgrade. We have the automatic transfer switch here, which is going to put everything into one box. When I start the generator, it'll automatically sense that I don't have to come out if it's raining and so forth to put this in.

So when it gets into the electronics like this area here, this is a little bit more than my pay grade. I'm going to bring Steve, our certified RBA technician in and have him change out our switch here and put this automatic transfer relay in. Today we're going to be upgrading this system to an automatic transfer switch. Much more efficient, you're not going to need to go outside and unplug the unit from the shore power and plug it into the four by four box to start your generator. So basically what we're going to do is first thing I want to do is verify that we've killed all of our potential power sources.

We could have power coming from a batter bank, from an automatic generator switch or from the shore power. So what I like to do is unplug the shore power. I verified that the generator is disabled. We're going to put this out here so I can keep an eye on it, so nobody inadvertently plugs it in. Now we're going to remove these four by four boxes while we're wiring and then install this automatic transfer switch.

Now we get our shore power coming in here. This is going to our distribution center. This set of wires is coming from our generator. The automatic transfer switch has decals on it, shows us where exactly everything goes. You need to pay attention to that, make sure you don't hook it up incorrectly.

See, at this point, we've got our wire nets, see it's right tube from the shore power to our load center wiring. They're all going to be separated. Got our wires marked, so we know who is who. We've got to pop the box connector off right here. Set down aside for use later.

Pop these little animals out. Be cautious that you're not going to skin any of the insulation off of your Romex wiring. Remove the wires coming from the generator. Now we can get this whole 30 amp outlet out of the way. Get a Romex connector out.

And be cautious of just getting the insulation off of your wiring. We can set that aside. Now, what we're going to do is we're gonna take this ATS box, as you can see we've got several variations of knockouts around all four sides of this box. We're going to figure out what the best geometry is, what knockouts to take out so that we can have it fit in the box and have our wires' feet into this box correctly. Looks uniformed, looks like somebody knew what they were doing.

See here we can see we our box, this is where our generator line is going to come in. The hot neutral is going to go to these two. Here's our shore power cord right here. That's going to go to the hot neutral in the center. This is our load center panel.

This is going to be our hot neutral right there. Because it's plastic, we don't have any bonding wires like the metal boxes had, so we don't need to use those. But we will use the grounds from each three sets of wires. So now I'm going to take and figure out which knockouts I want to take out. And it may be, you might have to readjust your box connectors to get them longer.

Sure, you may have to strip some wire, cut it so that it fits in nice. And this is something you don't want to be in a rush. You just want to take your time, do it right. It'll make the job go a lot easier. So we've got our shore or panel, so we can feed that up.

This is 10 gauge wire, so it's a little tough to work with. So you can see, with this 10 gauge wire, it's rather stiff. We're going to, we've got three points of entry that we have to bring our wires in. So we've got one knockout here, our wire's plenty long, but we're going to just take out a knockout over here and be careful when you're punching knockouts. Everybody gets in a hurry with a screwdriver.

There's a chance you could damage the contactor. You've got an electronic control board down here that you could damage, so just be real careful. Especially the metal ones. You don't want the metal plug to end up inside in the electronics. So we've got one more to take out.

That should be our three entrance holes. So we've got our three plugs out now and looking at the board, I've got, this is where my load center's going to come in at. So I'll bring that wire in through here. This is where our generator is gonna feed. It's gonna come over here and then down under here and our shore power will come up right through the center.

So the shore power is probably the heaviest wire to work with, so that's the one I'm going to do first. We're going to bring that in right through the bottom here. So this is our box connector. We'll bring that through and we're going to need to slip the nut over the wires. Just like that.

We'll feed that through. We can always shorten our wires later if we need to. We're gonna leave it a little loose right now, in case we have to adjust things. There you can see here, shore power right here, I did say I was going to put that in last, but we're going to put that in right now. So we'll put our ground in first.

And this is our ground leg on the bottom here. A little bend in it. Draw that down. These screws should be torqued at 17 inch pounds. You don't want to overdo it, but you don't want them loose.

I always like to check them to make sure they don't work out. The nice thing about the power cords is the wires are tinned. They've got a little solder on them, so it gives it a little more strength. So now we're going to hook up our hot and our neutral and we can see here, you can kind of see, you've got black and white, black, white. Here we are shore power again.

This is going to be our hot, bring that in. Draw that down. Got our neutral wire. Another thing you wanna be careful is if you don't have a very long strip here, you do not want to draw that screw down over the installation where you have a poor connection. That can create heat and heat creates fire.

Wanna make sure you get that under the metal or the solder and not the insulation. So we've got our shore power wires hooked up. Now we're going to come in and we've got our generator wires coming in here. This is our generator set right here. What I'm going to do is straighten these out a little bit.

You can see that there's some kinks in those wires. If you can straighten those up, it'll make it much easier to install them into the new ATS box. So we'll just kind of straighten those a little bit. The other thing to notice is on this ground wire, they have what's called spaghetti tubing. This is actually a little bit of insulation that's right here that is required by code.

So that in the event this wire were to touch a hot spot anywhere inside this box, it would not create a short. So spaghetti tubing is required by code. We're going to bring that in and it's going to go down in here to the generator slot. This is 10 gauge wire again, so it's rather stiff. So you want to be nice and careful with it.

We'll get that box connector set. That snapped in good. Now we've got our three wires. We've got our hot, our neutral and our ground. So that looks like the hots right here, there's our neutral.

So we're going to put the neutral in first, because that's the furthest away. It's nice to have a pair of long nose pliers, or duckbills. So we've got that in there. Make sure you get it in there in place. We'll draw the neutral down.

And we'll bring the hot around. Snug that up. And we have our ground left and this is our ground bus down below. Find a nice path to bring it through. Put a little bend on it, so we can hopefully walk that up into that bus.

Okay. We just made it in. Get that one ground tightened up good. Now what we've got left is the load center and that's this last set of wires we have. Flip our box around, so we can see it a little better.

There's our load center wires. They're going to go on this last set right here on top. I want to be careful in putting her, put them in there, 'cause there's other components down there that you could damage. So we're going to bring that in. Get it snapped in.

Knot the ground up first on this one. And we've got our hot our neutral left. The hot one's on the inside, so we'll do that one first. Again, this 10 gauge wire is kind of difficult, but it does carry a lot more current, much safer. We got that guy in.

Now we've got out neutral left. Okay. That should be all the wires are connected. Now what I'm going to do is just come back, check my wires, make sure I got everything tight. Everything looks good.

So we've got all of our wires hooked up. We've got our generator wires connected, we've got our load center connected and we've got our shore power connected. Now it's going to take a little time for me to get this mounted and I'm going to clamp it, adjust the wires a little bit, tape the convoluted tubing. But now what I want to do is I want to plug it in and verify that I do have current coming from the shore power out to the load center. That's my first test.

The last test, we won't do that today, but the next test would be now when the generator starts, if you're plugged into shore power, that will automatically disconnect the shore power without you having to go out there and unplug it. The generator will kick in and that's a good feature so that if you do lose power, it's raining outside or it's miserable. The campground loses power, that generator, you start it up. It's going to automatically switch over. This box has a 20 to 30 second delay before that happens.

And when that happens, you'll hear this contactor pull in. We're not going to do that today, but the contactor will pull in and then it'll just transfer power from shore power to generator. So basically that's what it is. It's a wonderful feature to have. If you don't feel comfortable doing this kind of work, you can always take it a shop.

But if you're handy, if you've put in added circuits in your home or something, it's pretty straightforward, not real high tech. You just have to be cautious, be aware that you are working with alternating current. It's much easier once you've installed this device, whether you install it, or have a service center install it, it's going to make your camping experience much more enjoyable. You're not going to have to go out in the rain to pull your power cord out of your shore power pole, bring it around, plug it in the four by four. It's just going to make it a much better unit and experience for you.

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