Adding a 30 amp RV outlet in my garage

[Archicamper]

I have an old style 30 amp dryer outlet in my laundry room adjacent to my garage that I would like to use to power an RV outlet in an existing box in my garage. My house is all conduit and there is an existing conduit between these two outlets.

When I pulled the dryer outlet, it is wired using the old standard of two black hots and a white neutral wire. The hot wires are 10 or 8 gauge but the neutral is a 14 gauge wire. For a 30 amp RV outlet I believe the neutral should be the same gauge as the hot. What I would like to do is use one of the hot wires as a neutral back to the panel.

At the panel, I will replace the double pole breaker with a 30 amp breaker and move the unused hot wire to the neutral bus taped with white tape to indicate it is a neutral wire.

Back at the dryer outlet I want to pull an 8 gauge hot and neutral from this outlet to the outlet in the garage where I will be installing the 30 amp RV outlet. The wires hot and neutral (former hot taped white) will be spliced at the dryer outlet with the new wires from the garage.

Cover plate at the dryer location and wire the RV outlet in the garage and I should be done. The conduit will serve as a ground for the circuit. I have not seen anything exactly like this when searching the forum.

Does this make since to retrofit a 30 amp RV outlet in my garage?

[jtstromsburg]

Sounds about right to me, but I think you'll still want more than 14g for a ground as well. I'm sure others will chime in with more knowledge and existence then me though.
Good luck

[TURBS]

personally I would match the ground to the other wires but thats just me.


TURBS

[SteveBingham52]

If I understand you mean to use the conduit as the ground with no actual ground wire pulled? Major infraction and unsafe. Conduit is grounded yes but should not be used as the main current return. Violates both NEC and NFPA codes. Not a problem if you don't have a problem but if you do and inspector finds it insurance is no longer responsible.

[gasman6674]

If its all conduit just pull the proper ground. I would pull a neutral too but thats just me.

[Archicamper]

I believe that NEC allows EMT conduit to be used as a ground with metal boxes. There is a hot and neutral wire in the conduit. Not saying that a separate ground wire is bad idea but, my whole house was wired by a union electrician with EMT conduit without any ground wires in the conduit.

[clange]

I'd pull a ground wire, too. If the conduit were to break at a joint or in some other way lose connection somewhere between your box and the breaker panel it could be lights out for you or one of your loved ones if you have a wiring problem or short with the TT.

[rockin'ray]

I am not up to date on electrical code, but i would not think it would pass for the simple reason that if you get a break in the conduit or take a piece out of that run, then you lose the ground path back to the panel. In Canada you once used to be able to ground your panel to the nearest cold water line in your house as long as you put a jump wire across any water meter. They since changed this becaue a break in the line and you lost al grounding for your panel and you have to run a solid line to the service side of your water meter. I would run a separate ground conductor as well.

[VinceU]

From the Wik, many local codes require a ground same as conductors

Conductors installed within conduit cannot dissipate heat as readily as those installed in open wiring, so the current capacity of each conductor must be reduced if many are installed in one conduit. It is impractical, and prohibited by wiring regulations, to have more than 360 degrees of total bends in a run of conduit, so special outlet fittings must be provided to allow conductors to be installed without damage in such runs. Some types of metal conduit offer a useful bonding conductor for grounding (earthing), but wiring regulations may also dictate workmanship standards or supplemental means of grounding for certain types. While metal conduit can be used as a grounding conductor, the circuit length is limited. A long run of conduit as grounding conductor will not allow proper operation of overcurrent devices on a fault, for example.

[wmtire]

The following oft-quoted website has a plethora (Love an opportunity to use that word) of information on RV related electrical situations.

RV Electric

You can peruse around the website at your leisure.

I would definitely check the "ground wire on appliance service" link that is on the left hand side of the main page of the above link. It gives some interesting history (if factual) on the subject.

[Coops1]

Here's the deal... as per the NEC & CEC

If your pipe is emt with steel boxes there is no issue with bonding the outlet to the box, the proper size of wire would be #12 for this.

The only code you will be breaking is identifying your neutral white with tape.

[fast murray]

Assuming when you say the house is wired in conduit, you are talking about EMT, NEC article 358.60 says EMT shall be permitted as an equipment grounding conductor. If you want to pull a grounding conductor in, Table 250.122 says the minimum size of copper conductor permitted on a 30 amp overcurrent device is #10. As far as using one of the black wires as a neutral, Article 200.3(A) says that conductors size 6 and smaller shall be identified with a continuous while or gray outer finish or by 3 continuous white stripes on other than green insulation along its entire length.

If it were me, depending on the length of the circuit, I'd pull in a #10 green grounding conductor just to be on the safe side and while I was at it I'd replace one of the black hots with a white and get rid of the #14. If it's #8 wiring now you, you can replace it with #10 wiring which is good for 30 amps.

[lswartz]

Unless you are going to run the AC or the electric WH why do you need 30 amps?

[fast murray]

If there's a conduit running there and all you need to do is pull in the wire, why not? I've replaced several receptacles and cord ends after they fail trying to carry loads that the owner never planned on using but "figured it should work." We usually do that while we're out putting in a dedicated circuit with the proper recep.

[Archicamper]

I understand the logic here. I hate to have to buy 75 feet of black, white, and green 10 gauge wire and waste the wire already in the conduit. The other concern that I have is pulling that much wire over that distance. There are already some 14 gauge wires in some of the conduits. I will need to check and see what pull boxes are along the route.

[Archicamper]

Originally Posted by lswartz

Unless you are going to run the AC or the electric WH why do you need 30 amps?

I figure if I am going to do this I want to be able to run whatever I want in the trailer.

[VinceU]

Originally Posted by Archicamper

I understand the logic here. I hate to have to buy 75 feet of black, white, and green 10 gauge wire and waste the wire already in the conduit. The other concern that I have is pulling that much wire over that distance. There are already some 14 gauge wires in some of the conduits. I will need to check and see what pull boxes are along the route.

How bout just installing a new fashioned plastic conduit with the three leads? Less chance of damaging or overheating the conductors in the original runs.....just suggestin..

[Archicamper]

Originally Posted by VinceU

How bout just installing a new fashioned plastic conduit with the three leads? Less chance of damaging or overheating the conductors in the original runs.....just suggestin..

Not allowed by code where I live.

I understand the concern with conduit as ground but stepping back and looking at this, the RV outlet that I will only be using several times a year mostly for my personal comfort while loading and unloading the trailer would have a ground wire to be fail-safe but, every other outlet in my house which I use every day are grounded through the conduit.

If this is a real issue, I am focusing my attention in the wrong place.