Temp. electricy to the coach

[Morich]

Wire it wrong, or have something loose or come loose in the house wiring feeding the dryer outlet and/or in the RV, and you could electrocute someone, maybe a loved one such as a child.

Got to agree with this as it applies to pretty much any electrical work we do! I always try to keep in mind that 110 AC is by far the most dangerous to many of us because it is so common we forget to be safe but it is also the more likely voltage to cause heart fibrillation. The big stuff like 7600 is more likely to burn an arm or leg off but the 110 just goes straight to killing.

[Goodspike]

Originally Posted by al1florida

I believe the key info I am trying to convey is that in a 3 wire 220V dryer outlet the ground wire may be a smaller wire and it could be dangerous when used as a neutral instead of a ground and the RV is pulling current approaching 30 amps. We could also get into the situation that there isn't a separate non current carrying ground wire from the dryer plug back to the C/B panel. The ground wire would be taking the same path as the neutral wire would be. Unless a separate ground wire is run.

I think we both agree that you should not connect an RV to a three wire system. I would say that even if the "ground" wire were larger than the others. You really should have a dedicated neutral and dedicated ground when you're dealing with that much current. I can sort of see why the old fashioned dryers didn't, but really an outlet should be setup to deal with whatever is plugged into it. Maybe way back then it was.

I am guessing the "three conductor cable" is a 220V outlet with a ground wire.

Nope, although technically you could have 220 volts if you connected things up right (or wrong, depending on what you're trying to do).

I first ran into this at a 1960s apartment complex where the wiring was run through conduit. The broke the bar on the lead side of the outlet so the top and bottom were separate, but not on the common side, so something plugged something the top outlet was a different circuit than something plugged into the bottom outlet. Not sure why they cared, other than it did save pulling one wire though the conduit. This was a 1960s building so there were only two outlets in the kitchen, plus the refrigerator outlet, all set up so each was on two different circuits.

Now that I think about it, I had a 1960s condo that part of it was the same way, but outside the kitchen. Again conduit, so it probably did have to do with pulling the wires.

The second time was when I remodeled my current home's kitchen and had to bring it up to code. That required six additional circuits! Anyway, two of them were brought in on the 3 wire plus ground setup. Not sure why more weren't. Anyway, made one less cable to pull.

[Goodspike]

Originally Posted by Morich

Got to agree with this as it applies to pretty much any electrical work we do!

It's not just electrical work, it's using electrical systems.

Many here suggest checking the power at RV camps with a tester because so much of it is poorly done. The same can be true at homes. It's mainly older homes, but a surprising amount of outlets have open grounds or reversed load/common. So yeah, if you have a tester to use at an RV park, use it on that outlet you use to connect an RV to a home. Dryer outlets tend to be changed out less by homeowners than other outlets in the home, but there's nothing to say the original electrician did it right!

Another electrical story. I had a friend who rented his first apartment from a real slumlord. The apartment had no heat! The neighboring unit had no exterior doors or windows other than the front door. Clearly not a place up to code.

Anyway, if you touched the stove and the kitchen sink you'd feel a bit of current. I never helped him fix it since it wouldn't have been legal for me to do so, but I suspect a ground and common were crossed at some point.

BTW, just to be clear I'm not an electrician (as my use of the numbers 110 and 220 and other terminology probably show), but I do like to understand things so I tend to research how electrical is supposed to be done.

[Wyatt]

Originally Posted by Morich

As Thom states, it depends on what they have and how much you want to go to getting it to the RV.
Considered tapping the drier connection, if they have electric drier or the hot tub if they have one? Any heavy duty power tools in the garage so they have high current outlets? Look for the highest power outlet that you can reach but often that will only be 15-20 amp and that should not be used for air as it may start the air really slowly and lead to overheat and failure.

That’s true. If you can tap into your friend’s dryer plug, that would be ideal, as they are NORMALLY a 30 amp socket. But, the household 30 amp plug, is not the same 30 amp plug that you have in your RV. So a standard dog bone connector for RV’s won’t work connecting to a home.

[Goodspike]

Originally Posted by Wyatt

That’s true. If you can tap into your friend’s dryer plug, that would be ideal, as they are NORMALLY a 30 amp socket. But, the household 30 amp plug, is not the same 30 amp plug that you have in your RV. So a standard dog bone connector for RV’s won’t work connecting to a home.

Those aren't the same because the dryer is 220 volt and the RV 30 amp is 110. But even my 110 volt 3000 watt generator doesn't have the same plug as an RV. It uses a twist connector.

[Wyatt]

Originally Posted by Goodspike

Those aren't the same because the dryer is 220 volt and the RV 30 amp is 110. But even my 110 volt 3000 watt generator doesn't have the same plug as an RV. It uses a twist connector.

You’re right, I forgot about that. If it’s a 220v dryer outlet, you’d actually have to disconnect one leg of the feed, and then figure out some type of adapter, probably have to make one yourself.

I wonder how many amps a 110 dryer outlet could handle? I imagine that they’re rather far and few between anyway.

[Goodspike]

Originally Posted by Wyatt

You’re right, I forgot about that. If it’s a 220v dryer outlet, you’d actually have to disconnect one leg of the feed, and then figure out some type of adapter, probably have to make one yourself.

You would just get a 4 prong male plug and a 3 prong female plug and wire them together with a three wire (including the ground) cable of sufficient gauge. The one prong of the plug wouldn't be connected to anything but would only be live inside the male plug, so not an issue.

[Wyatt]

Originally Posted by Goodspike

You would just get a 4 prong male plug and a 3 prong female plug and wire them together with a three wire (including the ground) cable of sufficient gauge. The one prong of the plug wouldn't be connected to anything but would only be live inside the male plug, so not an issue.

Great idea. Does anybody sell those that you know of? If not, I guess I’ll make one. Be nice to have when staying over in somebody’s driveway overnight, if it were hot outside...

[Morich]

This seems to have spireled off into way too much techie thinking but missing the simple stuff.
It is not something everybody should do, especially if they do not understand what it requires, so keep that foremost in mind but let's do the simple thinking.
What do we do when we want a totally new 30 amp circuit run straight from the breaker box? We put in a three wire of correct size for the use and distance, tie one wire to power, one wire to neutral and another to ground if we want to stay close to most codes.
We know that the ground and the neutral both go to ground in the box making them very much the same but adding a layer of safety.
So if we open up a 220 drier outlet that is fed by two 30-60 amp breakers, we find 2 wires that have power, protected by whatever size breaker (30-60?) and a ground wire. or neutral depending on how you speak, since both neutral and ground wires are connected to ground at the breaker box.

So what do we need to run an RV? Power source/ hot wire or whatever we want to call it and ground/ neutral or whatever you want to call it but keep in mind that it is tied to the same thing in the breaker box and makes little difference. If you are concerned about the neutral versus ground, then you need to run a wire back to the box and lay it down on the lugs with the wire you have in the outlet. That gives you two paths back to ground if that makes you feel better but for operation, it changes nothing.
It is only moving the location where we pick up the hot and ground from the breaker box to the outlet. When you use a two wire extension cord, it doesn't bother you that it doesn't have both neutral and ground.
If it is something that you want to make up a plug for repeated use and to avoid getting into the backside of the outlet, find a plug that fits and only wire the lugs you want to use, plug it into the outlet and leave the drier outlet wiring alone.
But I say again, DON'T do it if you don't understand!

[Goodspike]

Originally Posted by Morich

So what do we need to run an RV? Power source/ hot wire or whatever we want to call it and ground/ neutral or whatever you want to call it but keep in mind that it is tied to the same thing in the breaker box and makes little difference.

I'm not so sure it makes "little difference." The neutral lines can be carrying power back to the breaker box. The ground wires would typically be dead in almost all scenarios.

If you've ever worked on a dead circuit that shares a neutral with another circuit you may have noticed a tingle off the neutral line. That can be startling because you thought you had the power off!

So if we open up a 220 drier outlet that is fed by two 30-60 amp breakers, we find 2 wires that have power, protected by whatever size breaker (30-60?) and a ground wire. or neutral depending on how you speak, since both neutral and ground wires are connected to ground at the breaker box.

Actually hopefully you will find both a neutral and ground, and in newer systems you would. As noted above I'd I'd not use a three wire drier connection period. If you did, one of those three house wires would not be in use and you'd effectively have only a two wire system. More on that next.

When you use a two wire extension cord, it doesn't bother you that it doesn't have both neutral and ground.

Two wire extension cords are typically light weight (low gauge) 110 volt items connected to a 15 or 20 amp circuit. They are only designed to be connected to devices that do not require a ground (devices with two prong cords). An RV is designed to be connected to a three prong cord and it is often connected to a higher amperage breaker than a two prong extension cord.

[Goodspike]

In this other thread ongoing a user was having slight voltage from the shell of their RV. Turned out at least part of the problem was an open ground in the outlet they were connecting the RV to. Connecting an RV to a 3 wire dryer connection would likely cause the same issue. In effect either would be just a two wire connection.

https://www.winnieowners.com/forums/...ml#post3864039

[Sheilag1848]

When I visit my eldest son he has a 110 plug outside. I use reducers to connect to it just to keep battery and refer going. When its hot I just run my genset

[RTrider]

I installed 2 20 amp circuits in my garage to run shop equipment. I made sure they were on "opposite legs" of power. I built and adapter that has 2 20 amp male plugs. The adapter ties grounds together and neutrals together and connected to a 50 amp female receptacle. When the MH is parked for loading, I plug the adapter into the two 20 amp outlets and the MH into the female 50 amp. It works well as long as care is used on what electrical components are active. What you have to know is the power monitor in the coach thinks it has 50 amps available, so it will not load shed. Ultimately, it is still safe because the 20 amp breakers would trip if too much load is put on the circuit. Once the batteries are at full charge, I can actually run both A/C units.

[Shedboy]

3 wire 220VAC moochdock - BEWARE!


Lots of good info as well as misguidance in this post(s). I caution you to very careful if you are connecting to a 3 prong 220 VAC outlet (no separate ground 4th wire). Doing so will probably cause a GFI to trip (if there is a GFI). If you are considering hooking to 3 wire 220VAC, first take one of your battery jumper cables and connect it to the RV steel frame and clamp the other end to a metal water pipe. This will simulate the missing 4th wire.



Each "thing" in your RV with a 3 or 4 prong plug is expecting to find a ground wire that is separate from the neutral wire in a 3 wire 220VAC socket. By not providing the separate ground wire to your RV, it is possible that the RV itself will float e.i. will assume a voltage. You would find this out by having one foot on the steel entry step and the other foot on the ground. Your body would assume the function of the 4th wire (an electrifying experience). Also could happen grabbing the entry assist bar on the RV if you have one.


One other note regarding tapping into 2 separate 110 vac plugs to obtain 220VAC. The total amperage available would be less than 50 amps, so you would get 220vac at maybe 20 amps.
If one of the 110 plugs was a 20 amp circuit and the other a 15 amp circuit that's what you would get. Morich has the right idea, if you don't know what you're doing, best leave it alone.

[Goodspike]

Originally Posted by Shedboy

3 wire 220VAC moochdock - BEWARE!


Lots of good info as well as misguidance in this post(s). I caution you to very careful if you are connecting to a 3 prong 220 VAC outlet (no separate ground 4th wire). Doing so will probably cause a GFI to trip (if there is a GFI). If you are considering hooking to 3 wire 220VAC, first take one of your battery jumper cables and connect it to the RV steel frame and clamp the other end to a metal water pipe. This will simulate the missing 4th wire..

I think it's best just to avoid those 3 wire 220 volt circuits. I've seen old houses with metal plumbing where someone did a repair by putting in a section of plastic pipe, and as I recall it was near where the main line of water came in, effectively wiping out most it's function as a ground. And of course there are metal spigots that are connected to plastic pipe, that's fairly common both in new houses and outside runs.

Now if you were to bolt a grounding cable to your frame and pound in a grounding rod . . ..

[orangeminnie]

Bottom Line: If the dryer receptacle has 4 prongs, the circuit can work safely for an RV. You'll need to create an adapter dogbone of your own. The dryer will be on a 240V 30A breaker, so you still may be limited as to what appliances you can run at the same time.


If the dryer receptacle only has 3 prongs, don't use it.

[Goodspike]

Originally Posted by orangeminnie

Bottom Line: If the dryer receptacle has 4 prongs, the circuit can work safely for an RV. You'll need to create an adapter dogbone of your own. The dryer will be on a 240V 30A breaker, so you still may be limited as to what appliances you can run at the same time.


If the dryer receptacle only has 3 prongs, don't use it.

Yes, I would only add you could create your own adapter to make a 30 amp 120 volt line for a smaller trailer, and shouldn't have any limitations that you wouldn't have connected to a trailer park 30 amp outlet (and probably fewer given what parks can be like).

[Morich]

Lots of folks who show a lack of understanding, so I might try to explain it more clearly.
First if you do not understand what you are doing, DO NOT do it!!
But if you understand and know what you are doing, this is a simple matter of rewiring the existing wires at the plug and breaker panel.
Wire by wire to make it plain?
A circuit is a circle and needs two wires, commonly called hot and neutral and then when we want more safety, we add a third we call ground.
On either a three or four post outlet we have those available---if we want to do the work to use them. First remember it takes three wires to run a single 110 Volt circuit with the added safety of the separate ground! So is it difficult to imagine how to use three of those wires at a drier outlet to get power to an RV?
Use the three wires and wire it as it was done before the four wire outlets came into the code!
Again, I state, if you do not understand, DO NOT do it !
But that doesn't mean it can't be done, just that you can't do it!

[Goodspike]

Originally Posted by Morich

But if you understand and know what you are doing, this is a simple matter of rewiring the existing wires at the plug and breaker panel.

While it would be technically possible to easily reconnect a three conductor outlet and change it from 240 volt 30 amp to 120 volt 30 amp, it would then no longer function as a dryer outlet. So I don't really see that as a viable solution. Not many people are going to want to rewire their breaker box every time they connect their RV.

In most cases it would probably make more sense to simply add a new 120 volt 30 amp circuit, assuming there's space/capacity in the breaker box, which would probably be the likely in most situations. That would allow the original dryer outlet to continue serving its original function and also allow an outlet placement for the RV circuit which is more ideal. That would almost certainly require a permit, but at least you'd have a fully functional and safe RV outlet. And the outlet could even be the RV style outlet.

[orangeminnie]

Originally Posted by Morich

Lots of folks who show a lack of understanding, so I might try to explain it more clearly.
First if you do not understand what you are doing, DO NOT do it!!
But if you understand and know what you are doing, this is a simple matter of rewiring the existing wires at the plug and breaker panel.
Wire by wire to make it plain?
A circuit is a circle and needs two wires, commonly called hot and neutral and then when we want more safety, we add a third we call ground.
On either a three or four post outlet we have those available---if we want to do the work to use them. First remember it takes three wires to run a single 110 Volt circuit with the added safety of the separate ground! So is it difficult to imagine how to use three of those wires at a drier outlet to get power to an RV?
Use the three wires and wire it as it was done before the four wire outlets came into the code!
Again, I state, if you do not understand, DO NOT do it !
But that doesn't mean it can't be done, just that you can't do it!

3-wire dryer outlets have no ground pin (2 hots and a neutral). Unless this house has a very old dryer, it will be using a 4-pin outlet.