power supply for RV - Electrician Talk - Professional Electrical Contractors Forum

selectfew · 06-23-2009, 11:17 PM

I have to do a service call for a couple who would like to have 30 amp receptacle power plug for their traveler trailer. It's about 100'from the panel to the area of the RV. I thought about also adding a regular receptacle for them but I'm not sure. I'll be running PVC the whole way and used 8-3 for the sake of voltage drop. I could used romex in the PVC. And I have to do some trenching up under the driveway and walkway. I can see the money now.

Do you have anything to suggest or other ideas.

480sparky · 06-23-2009, 11:21 PM

Quote:

Originally Posted by selectfew

I have to do a service call for a couple who would like to have 30 amp receptacle power plug for their traveler trailer. It's about 100'from the panel to the area of the RV. I thought about also adding a regular receptacle for them but I'm not sure. I'll be running PVC the whole way and used 8-3 for the sake of voltage drop. I could used romex in the PVC. And I have to do some trenching up under the driveway and walkway. I can see the money now.

Do you have anything to suggest or other ideas.

Forget the 8-3. NM can't be used outdoors or underground. Even if you mean UF, it's a pain to pull into PVC.

Use THHN/THWN.

If the plug is a NEMA standard 120/240 recep, you'll need three 8s. If it's a TTL-30 recep., then you only need two as those are 120v only.

If you want a 'regular' receptacle, you can't use the 8s unless you plan on landing them in a panel with fuses or breakers. Then you're adding a couple 12s or 10s to the run, and derating and race way fill will need to be addressed.

selectfew · 06-23-2009, 11:38 PM

Quote:

Originally Posted by 480sparky

Forget the 8-3. NM can't be used outdoors or underground. Even if you mean UF, it's a pain to pull into PVC.

Use THHN/THWN.

If the plug is a NEMA standard 120/240 recep, you'll need three 8s. If it's a TTL-30 recep., then you only need two as those are 120v only.

If you want a 'regular' receptacle, you can't use the 8s unless you plan on landing them in a panel with fuses or breakers. Then you're adding a couple 12s or 10s to the run, and derating and race way fill will need to be addressed.

I brought up about adding the regular receptacle since I always known
RV trailer park to have a power supply and a regular receptacle. However I don't think it would be necessary because they have a regular plug mounted on the trailer.

MDShunk · 06-23-2009, 11:44 PM

Check your supply house for a "Midwest box" (has a duck head logo embossed on it). It's a weatherproof-while-in-use RV receptacle. Midwest makes the coolest stuff for RV hookups, and they're not at all expensive. I think the 30 amp outdoor RV receptacle box is around 30 bucks, and it already has the receptacle mounted in it.

selectfew · 06-23-2009, 11:55 PM

Quote:

Originally Posted by MDShunk

Check your supply house for a "Midwest box" (has a duck head logo embossed on it). It's a weatherproof-while-in-use RV receptacle. Midwest makes the coolest stuff for RV hookups, and they're not at all expensive. I think the 30 amp outdoor RV receptacle box is around 30 bucks, and it already has the receptacle mounted in it.

Thanks for that Info; I'll look into that.

220/221 · 06-24-2009, 12:45 AM

Check voltage.

The last RV recep I did was 30 A 120V.

TOOL_5150 · 06-24-2009, 03:29 AM

Quote:

Originally Posted by 220/221

Check voltage.

The last RV recep I did was 30 A 120V.

That is the most common RV voltage/amperage

~Matt

LawnGuyLandSparky · 06-24-2009, 04:10 AM

Quote:

Originally Posted by selectfew

I have to do a service call for a couple who would like to have 30 amp receptacle power plug for their traveler trailer. It's about 100'from the panel to the area of the RV. I thought about also adding a regular receptacle for them but I'm not sure. I'll be running PVC the whole way and used 8-3 for the sake of voltage drop. I could used romex in the PVC. And I have to do some trenching up under the driveway and walkway. I can see the money now.

Do you have anything to suggest or other ideas.

Boy have I got the 30a single pole 120v circuit breaker for you...

nrp3 · 06-24-2009, 07:15 AM

Thats what those are for! Ah the light bulb comes on.

drsparky · 06-24-2009, 09:01 AM

100', 120v, 30A should be #6 AWG to maintain less than 3% voltage drop.

MDShunk · 06-24-2009, 10:53 AM

Quote:

Originally Posted by drsparky

100', 120v, 30A should be #6 AWG to maintain less than 3% voltage drop.

Maybe his voltage is high to begin with? Perhaps the voltage drop is quite tolerable to the connected load? Some guys get too wrapped up in this 3% drop stuff, confusing it with an actual code requirement.

drsparky · 06-24-2009, 11:32 AM

Voltage would have to be 139v to use #8. I

know the 3% comes from a FPN but I tend to follow them. Some of those RVs are well over $100,000, why get cheap on the wiring and risk a brown out. Your only saving a few bucks.

Loose Neutral · 06-24-2009, 12:28 PM

I have 10 wire from a single pole 30 amp breaker with the midwest receptacle. About 100-125' never had a problem. Most newer RV's have the regular 120v recep mounted on them. Not having the 120v recep is not a problem for me, But is nice if your at a campground and using a lot of electrical cooking items. Those 120v recep's at the campground's are usually on thier own breaker though.