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Route 66 · 08-30-2010, 04:54 AM

Everything you need to know about RV electrical service.

paz · 08-30-2010, 05:26 AM

Quote:

Originally Posted by RickO

We will be spending a fair amount of time at my father in laws small farm in Minnesota and I just can't live on the 20 amp outlet next to the barn. I'm going to have an electrician install a dedicated outlet for my 40' DP but have a few questions:

1) The house is nearly 100 years old. I certainly don't want to tie into anything that's been there that long so plan to have the new line run directly from new breakers in the service panel, under ground to a pole near where I'll be parking. Question is... since we're really starting from scratch here is there any reason NOT to put in a 50 amp rather than 30? I'm assuming there's an extra few dollars in material but shouldn't the labor be about the same?

2) I plan to do the grunt work to keep cost down so I'll be digging and recovering the required trenches... about 100'. Am I over simplifying this or should an electrician be able to install the breakers... run the cables... and install the receptical within 3 or 4 hours?

I've found several good references here that I can print and provide the electrician on the proper wiring but I'm trying to estimate how large of a bill I'm signing up for. I'm guessing $250 in material and since it's a rural area, about $80/hr for the electrician... or, something just over $500 total. It's no small sum but considering we average nearly $30/day for campground fees it pays for itself pretty quickly.

Thanks in advance for any insights.

Rick

PS.... we plan to be nowhere near Minnesota in the winter but do need all the A/C we can get in the summer!

Does your father-in-law's house have sufficient power for itself AND 50-amp service to your RV? As someone already mentioned, 50-amp RV service is really 100-amps. I'd check before tying into the main panel.

Many older homes only have 150-amp (or less) service to the whole house. If that home has modern conveniences inside, it may already be at or near the power limit. If your RV draws even only 50 or 60 amps, you may overload the wires coming to the main panel and you'll possibly blow the main breaker.

You say you are planning to run a new line from the service panel to the pole where you'll be parking, but you may need to run new lines from the street to the house first.

RickO · 08-30-2010, 08:29 AM

Quote:

Originally Posted by Route 66

Everything you need to know about RV electrical service.

Thanks so much Dirk... that's perfect. I was surprised to see that the wire sizing chart calls for #4 wire for a 120v 50amp 100 foot run though. Hmmmm.... they seem to call for a much heavier wire that most on this thread have proposed.

RickO · 08-30-2010, 08:32 AM

Quote:

Originally Posted by paz

Does your father-in-law's house have sufficient power for itself AND 50-amp service to your RV? As someone already mentioned, 50-amp RV service is really 100-amps. I'd check before tying into the main panel.

Many older homes only have 150-amp (or less) service to the whole house. If that home has modern conveniences inside, it may already be at or near the power limit. If your RV draws even only 50 or 60 amps, you may overload the wires coming to the main panel and you'll possibly blow the main breaker.

You say you are planning to run a new line from the service panel to the pole where you'll be parking, but you may need to run new lines from the street to the house first.

Thanks Paz. Clearly my next step is to verify the capacity of the main panel when I return there next week.

KC1BUD · 08-30-2010, 08:38 AM

Quote:

Originally Posted by RickO

We will be spending a fair amount of time at my father in laws small farm in Minnesota and I just can't live on the 20 amp outlet next to the barn. I'm going to have an electrician install a dedicated outlet for my 40' DP but have a few questions:

1) The house is nearly 100 years old. I certainly don't want to tie into anything that's been there that long so plan to have the new line run directly from new breakers in the service panel, under ground to a pole near where I'll be parking. Question is... since we're really starting from scratch here is there any reason NOT to put in a 50 amp rather than 30? I'm assuming there's an extra few dollars in material but shouldn't the labor be about the same?

2) I plan to do the grunt work to keep cost down so I'll be digging and recovering the required trenches... about 100'. Am I over simplifying this or should an electrician be able to install the breakers... run the cables... and install the receptical within 3 or 4 hours?

I've found several good references here that I can print and provide the electrician on the proper wiring but I'm trying to estimate how large of a bill I'm signing up for. I'm guessing $250 in material and since it's a rural area, about $80/hr for the electrician... or, something just over $500 total. It's no small sum but considering we average nearly $30/day for campground fees it pays for itself pretty quickly.

Thanks in advance for any insights.

Rick

PS.... we plan to be nowhere near Minnesota in the winter but do need all the A/C we can get in the summer!

Rick,

I would go with the others that said go with the 50 amp. I would also talk to the power company, they might give you a direction to go. They could provide at least an evaluation of what is there and what you need to do to get your service. I think this service is usually provided by the power company for free.

Ecker · 08-30-2010, 08:55 AM

Quote:

Originally Posted by RickO

Noted Ecker and thanks for the caution. As Clint once said, "a man's got to know his limitations" and I know mine. I certainly plan to engage a licensed electrician but can you expand about codes pertaining to RVs? I'm currently assuming that in this rural environment there is no way I can find anyone familiar with RV circuits but that I can print any number of documents available on this and other forums to serve as a roadmap for him. I'm acutally starting to learn a little bit about this stuff myself too so by the time we actually break ground I hope to be able to serve as a reality check to what he's doing.

The NEMA Code for RV's is contained in Article 551. Unfortunately, NEC code book is very expensive and I have never seen more than short excerpts in any Internet information. It is written in terms of installing service in an RV park so the main reason for finding an electrician with all around code knowledge is to ensure he understands the differences between straight home or commercial wiring and that required for an RV. I should add that not all jurisdictions adopt NEMA code, some do, some modify, etc so another reason to find a knowledgeable person so that install will meet your local code.

FleetMan · 08-30-2010, 09:02 AM

If you do not already have this link, check it out. It contains all the data you and your electrician will need for wiring up your RV circuit.

www.myrv.us/electric/

Workshop · 08-30-2010, 09:35 AM

Last year I had a cover installed in the back yard for my 5'er. I installed two hookup points, this one is near the house and allows the unit to be prepped for trips and when we have had friends stay a few days. One simular was installed under the cover. Each have water and cable connections.

I only added the photo to show the hook up and because someone suggested adding a 120v 15 amp and water as well. All parts were obtained from Home Depot and include a outside electrical panel because of the additional outlets under the cover and this allows me to control what I had powered when not in use.

The breaker panel is wired as a subpanel to the main panel...ensure you do that and run everything back to the main panel or another subpanel. The outlet boxes are 50 amp and 15 amp GFI and controlled by the individual breakers.

As the outlets near the house are within 20 ft....I used #6 wire to provide the 50 amps and used #6 to the cover 90 ft away. At that distance...I would have some voltage drop without increasing the wire size to #4 or #2 but didn't see the need to have 50 amps at that location. Checking the panel for amp use and voltage...have never used more than 32 amps at one time and the voltage is 2 volts less than the one near the house.

The outside breaker panel was less than $50 dollars with the breakers and worth the convience. If I had to do it again, I would have bought a roll of the #6 wire rather than buy it by the length as I was doing the project....would have been a lot cheaper. Everything was in conduit but you might consider direct burial and stub up within conduit going up if it works in your area.

I think 10/3 is to light for the 50 amps if I read the post correctly. If you are needing a strong 30amps....I would use something other than #10 considering the length.

As someone who does light remodeling...I would find the electrican that you want to do the job....find out what he will allow you to do or what you want to do yourself...and go from there. This way you have the post and outlet(s) height where you want and not where it works for them and ensure they know what you want before they start.

Theberrys · 08-30-2010, 10:18 AM

Here are a couple doc's that may be of assistance once you decide which way you can go. At the end of each is the reccomended wire sizes for the length of run.
Dick

Always-RVing · 08-30-2010, 10:26 AM

Concerns over the old house wiring capacity and age: Will it hold up to 50 amps?

That's 12,000 watts of power. That's a lot for a 100 year old home unless it has been updated. An electrician should be able to check the safety and usablility of the electrical wiring and service panel in the home. Your MH will need 50 amps if it has two air-conditioners. We have operated on 30 amp shorepower several times and kept a close eye on usage.

The Motorhome Magnum Inverter dial will let us select a shorepower max: 20 amp, 30 amp or 50 amp max.

Route 66 · 08-30-2010, 10:59 AM

Quote:

Originally Posted by RickO

Thanks so much Dirk... that's perfect. I was surprised to see that the wire sizing chart calls for #4 wire for a 120v 50amp 100 foot run though. Hmmmm.... they seem to call for a much heavier wire that most on this thread have proposed.

In relation to wire size, go by the charts. The longer the distance, the larger the wire. That way the voltage drop will be minimal and the wires will not overheat.

RickO · 08-30-2010, 11:45 AM

Quote:

Originally Posted by Batman_777

Concerns over the old house wiring capacity and age: Will it hold up to 50 amps?

That's 12,000 watts of power. That's a lot for a 100 year old home unless it has been updated. An electrician should be able to check the safety and usablility of the electrical wiring and service panel in the home. Your MH will need 50 amps if it has two air-conditioners. We have operated on 30 amp shorepower several times and kept a close eye on usage.

The Motorhome Magnum Inverter dial will let us select a shorepower max: 20 amp, 30 amp or 50 amp max.

Thanks Batman... I want no part of using any existing wiring from the house. When I get back there my first order of business is to check the state of the service panel and see what we've got. As pointed out earlier, all bets could be off if we're looking at a very old service drop. Otherwise I plan to come straight from the panel with all new breakers and probably 4/4 cable due to the ~100 foot run.

vermilye · 08-30-2010, 12:55 PM

"The NEMA Code for RV's is contained in Article 551. Unfortunately, NEC code book is very expensive and I have never seen more than short excerpts in any Internet information."

I believe you mean the NFPA NEC book. The entire code book is readable on line at the NFPA site. You do have to create an account but it is free. As of this date you need to switch to the 2008 edition since the 2011 is not yet available. Choose "View 2008 Edition On-Line"
The reader is a pain to use, will time out if you don't turn the pages fast enough, but is a lot cheaper than buying your own copy!

NFPA NEC On Line

RickO · 08-30-2010, 03:21 PM

Quote:

Originally Posted by vermilye

"The NEMA Code for RV's is contained in Article 551. Unfortunately, NEC code book is very expensive and I have never seen more than short excerpts in any Internet information."

I believe you mean the NFPA NEC book. The entire code book is readable on line at the NFPA site. You do have to create an account but it is free. As of this date you need to switch to the 2008 edition since the 2011 is not yet available. Choose "View 2008 Edition On-Line"
The reader is a pain to use, will time out if you don't turn the pages fast enough, but is a lot cheaper than buying your own copy!

NFPA NEC On Line

Thanks vermilye... yep, that's the site. I created my account and you're sure right about the reader being a pain to use. It's good background information.