Question about adding a 50 amp rv panel at our family reunion site.

[CJAG]

We have a reunion site in SE Oklahoma. There are several cabins on the property tied to one electrical system. There is one cabin that has a 100 amp panel in its home. My family wants me to tie into the underground wire about 50 feet from the cabin. Use lugs to connect to that wire and "T" it off to my pad 200 foot away. The wire is 4/3 to the home ( I think, getting final info on that soon).

For the record I will not be installing this myself. The site has several qualified elder statesmen who approve all work. I am a novice at this and I don't want to compromise the other cabins electric system. The problem is it is in the middle of nowhere so buying electrical parts at the time will be impossible, so I must prepare early.

I was hoping to tie a 50 amp panel for future RVs (I have a 30 amp trailer now). I have done some research and my run of 200 feet for the electric line is long. Also the wire to the home is only three strand and 50 amp wire is 4 strand. How can they tie into a hot lead from the 4/3 to my 6/4? I don't think it will be possible will it? I my only be able to do a 30 amp panel.

Do I add a box at the "T" with a breaker there? Or should we tap in underground and bury it all the way to my rv pad and add a breaker there?

Attached is a photo of the cabins panel not sure it will do any good.

 

[xrated]

Personally, I wouldn't walk.....I'd RUN away from the thought of doing this!

 

[CJAG]

My gut had me nervous. They all seem real confident in this method. Like they have done it a thousand times before.

 

[RRR]

"Know when to walk away, know when to run..."

 

[Mark_K5LXP]

There's "doing it" and doing it by code that is often very different. It's not clear where the service connect is for these structures, plus the question if the 3 wires are 120V with ground or 220V without ground. Neither one will get you the 50A drop you're looking for. The key issue is ensuring the RV connection point is safe. Unless one of these "elder statesmen" is an electrician or following the guidance of one, this isn't something you just show up and do without surveying the current installation.

Mark B.
Albuquerque, NM

 

[HueyPilotVN]

I am not trying to address the code compliance issues but here is a thread about how I carried a temporary electric hookup with me in my Stacker Trailer.

Scroll up to the start and skip the photoshop pictures, (they are directly inserted later in the write up).

Good luck and be careful with any hot components.

Temporary Electric Connections, (How to)

First a few disclaimers. This is a report on a practical way to do a temporary hook up to either a 30 or a 50 amp electrical service. It is not about meeting code for a permanent connection. If you are not comfortable with the safety issues involved then please get a qualified electrician. ...

www.rvforum.net

 

[CJAG]

There's "doing it" and doing it by code that is often very different. It's not clear where the service connect is for these structures, plus the question if the 3 wires are 120V with ground or 220V without ground. Neither one will get you the 50A drop you're looking for. The key issue is ensuring the RV connection point is safe. Unless one of these "elder statesmen" is an electrician or following the guidance of one, this isn't something you just show up and do without surveying the current installation.

Mark B.
Albuquerque, NM

Agree that is why I am here. They say one thing and I need reassurance if it will work. Which I am skeptical on now. I may have to look for another solution. The reunion park is adding cabins all the time so I am sure they know what thy are doing. However I also know they do not do everything by code. Heck we make our own septic systems using two 55 gallon plastic barrels for each cabin. The park is 50 years old and no issues with septic's anywhere.

 

[HappyWanderer]

But a backed up toilet isn’t going to kill you or burn down your RV.

 

[Rob&Deryl]

I would not “tee” the feeder. Not likely legal if that matters. I would drop a 50a breaker in the 100a panel and run to your pedestal.

 

[HueyPilotVN]

I agree that you should run from the existing panel with it's own 2 circuit breakers. That is what I did.

 

[Gary RV_Wizard]

That "Tee" would have to be an above ground junction box. There are industrial-grade methods of making waterproof and mechanically sound underground tees, but those are a stretch for amateurs electricians.

My guess is that underground run is 3-wire, 240v and the house has a separate ground rod of its own. Your Tee to the campsite would have to have the same, another local ground rod. That's not standard practice but it is allowed in certain specific situations, which may or may not apply here. I know how to make it work, but would have to think long and hard about whether it is an appropriate thing to do. My gut is uneasy about it.

Another 200 ft to the campsite is also a long run. How far is it to run from the source, either the house or the panel that feeds to the house? It would be much preferred to use one of those rather than a Tee.

I'm in the process of designing a 100 ft run of 4/3 with ground to provide 60A/240v power for a friend's workshop. That's from his main service entrance panel, not a tee. For your 200 ft run, I'd probably want 2 gauge instead of 4.

 

[John From Detroit]

Personally, I wouldn't walk.....I'd RUN away from the thought of doing this!

I will second that opinion.

I absolutly am against underground splices espically 3 way splices. Two way (Straint splice of a cutwire) Can be done with the proper overwrap (Which I just bought a box of) but not 3 way.(and I use mine on 12 volt stuff).

 

[AStravelers]

CJAG, are you aware that RV 50amp service is really a total of 100amp to the RV? I ask this as you stated that the cabin has 100amp panel, so you are potentially adding an additional 100amp load on the circuit going to the cabin.

 

[Gary RV_Wizard]

CJAG, are you aware that RV 50amp service is really a total of 100amp to the RV? I ask this as you stated that the cabin has 100amp panel, so you are potentially adding an additional 100amp load on the circuit going to the cabin.

If it is even remotely standard residential wiring, the "100A panel" in the house would be 100A/240v, so apples-to-apples vs the 50A/240v RV site. That said, it's still a major additional load on whatever is the source for that house panel.

 

[AStravelers]

If it is even remotely standard residential wiring, the "100A panel" in the house would be 100A/240v, so apples-to-apples vs the 50A/240v RV site. That said, it's still a major additional load on whatever is the source for that house panel.

Good point. I didn't think about that.

 

[Dprall]

50Amp breaker installed in the panel at the cabin. This answer assumes that the sub panel will have a three wire feeding it with a supply of 120/240 volts. To maintain the voltage to a 2.5 % drop at the end of the 200 foot run, you will need to use 3 runs of #4 copper wire and one #6 cu Ground. Cable suitable for underground direct burial or for installation in buried (Wet location) PVC conduit. #4 copper wire is rated at 85 amps, #2 aluminum is rated at 95 amps. The reason for the larger sizes in the wire is to offset the voltage drop over the distance. Also you would need 2 ground rods at the sub panel and the neutral bar and ground bar in the sub panel need to be separated (unbonded). You should check your local building codes and consult with a local electrician.

 

[CJAG]

OK after all your help and advice we are going to install a 30 amp Panel and tap into the panel at the cabin, too much for a 50 amp run. I will run a generator is necessary. Once again logic sets in on this forum. Thanks!

 

[SeilerBird]

CJAG, are you aware that RV 50amp service is really a total of 100amp to the RV? I ask this as you stated that the cabin has 100amp panel, so you are potentially adding an additional 100amp load on the circuit going to the cabin.

Wow, several months ago some genius argued with me vehemently that you could not get 100 amps out of a 50 amp service. He has not been around spreading misinformation lately.

 

[Sooeycute]

Just remember any time you install a 50 amp service for an RV you must use an RV panel. You are not creating a 240 volt outlet. Yes you have 2 110 volt hot legs which creates 240 at like a dryer plug or stove plug but you don't want to plug an rv into this. The 50 amp rv service splits those 2 hot legs into 2 separate bus bars. Each having 110 volt power. Plug into 220 and everything will run really fast for just a little while.

When I set up a service like this I put a 50 amp breaker in the panel and use direct burial cable like they use for a mobile home service. Its aluminum wire and much cheaper than copper.. Calculate the size to the run. Your RV will never be pulling nearly 50 amps.

 

[Gary RV_Wizard]

Just remember any time you install a 50 amp service for an RV you must use an RV panel. You are not creating a 240 volt outlet. Yes you have 2 110 volt hot legs which creates 240 at like a dryer plug or stove plug but you don't want to plug an rv into this. The 50 amp rv service splits those 2 hot legs into 2 separate bus bars. Each having 110 volt power. Plug into 220 and everything will run really fast for just a little while.

Sorry to contradict, but that is incorrect. Standard RV 50A service is 240v and exactly the same as a dryer or stove outlet. Both 120v and 240v are available with that type of electrical service. Yes, the load center (breaker box) in a 50A RV has two separate bus bars, but so does standard residential electric service. Each branch circuit can get either 120v or 240v, depending on the breaker type selected.

There are RVs that have one of more 240v appliances - that has become increasingly common in higher end "all-electric" models and may be used to power 240v clothes dryers or inductive cooktops.