Home Electrical Hook Up

Do what you want. The cost is in running the wire, not hooking up the box. I can always hook up a 15 or 20 amp receptical to compliment the 30 amp rv box.

I agree. If you are going to run 4 wires, install the outlet and breaker that takes all 4 wires. Done once and finished.

That is what I did. I have a 30 amp RV. For now. When I ran my power, I pulled three 6g wires (black, red, white) and one 10g wire (green), put in a 50 amp breaker, and a box with 50amp/30amp/20ampGFCI outlets and breakers. I will never have to touch that wiring again, no matter what I may buy in the future. It did not cost THAT much more to do than a straight 30 amp setup would have been.

(While doing this, I also ran a second conduit and installed a separate box with telephone line and satellite/cable coax. Like I said, done once and finished.)

Very good post, myredracer! You made it interesting, and very imformative for the OP, or anyone considering a home hookup.

Everything mentioned was important, hard to make it any more brief.

Jerry

OP, are you saying you have a 30 amp outlet already, but not an RV yet with two AC units and wondering if a 50 amp RV would get by at 30 amps with two AC units?

As mentioned previously, it depends on a few factors. You might get lucky, you might not. You can do things to improve the chances of it working with two. Proper voltage is critical. With AC units, as the voltage drops, AC units draw more current. AC units are rated to run at a nominal 120 volts. There are a number of sources of voltage drop from where your house connects to the power utility wiring on the street up to the power connection at the AC units themselves.

If you were to look at the AC unit electrical specs, you would probably find that by calculation, running two simultaneously is not possible on 30 amps. By code you would size the "main" breaker in the RV by taking the full load running current of the 1st AC unit (say 12 amp) and add the breaker rating for the 2nd (they're sized to min. to allow AC unit to startup) which would be 12+20 = 32 amps. So a 30 amp breaker "might" just make it. Note that this is at 120 volts nominal so as the voltage goes down, it will reach the point that it will take out the 30 amp breaker. In addition, you could also have other loads running in the RV like converter and fridge (on 120V) that will contribute to lower voltage. This is why it "depends"... Some will find it works, some won't.

If the voltage at the house panel is less than 120 volts, you have a lower chance. In the summer, if many other homeowners are running AC units in their homes, the voltage can drop. Can also drop in rural areas.

If the 30 amp receptacle isn't close to the house panel, you could have some voltage drop there. For longer runs, larger gauge wiring helps. If you need an extension cord, use min. #10 AWG, but even then it may not be enough.

Make sure plug blades on a shore power cord are kept clean. Dirty = voltage drop and heat. Never plug the shore power into a live outlet. Install a disconnect switch at home or shut a breaker off.

You may get the first AC unit running, but the second may not because an AC unit momentarily draws up to around 6 times the running current. The running current of the first unit + the 2nd at 6 times FLA may thus trip a 30 amp breaker. You could try a hard start capacitor if marginal to reduce the momentary inrush current. Also, make sure no other loads are running when trying to start the 2nd AC. Watch voltage level inside the RV *IF* you get two running. Running other loads (converter an exception if batteries charged) may not be possible.

Install a permanent voltmeter inside the RV to monitor the voltage. The best thing would be to install an EMS unit as it will automatically shut the power off it the voltage gets too low. Voltage under 105 will cause damage and eventual failure. Watch the reading on the voltmeter when you try and start the 2nd AC.

It is even possible, depending on the size of your house panel and total load calculation, that running two AC units in the RV is technically not possible and a house main breaker could trip when trying to start a 2nd AC unit in an RV. Having a 50 amp outlet (which is like 100 amps at 120V) could have an even higher possibility of tripping a house main breaker, esp. if you ran a bunch of other loads in the RV. If submitting a load calculation to the authority having jurisdiction, an RV outlet may not even be allowed, but I have yet to read of anyone doing this when installing an RV outlet (may not be exactly a legit. install).

ps: I did try to make this brief. :(

cooperrobt wrote:
I am having a 30 amp service box installed next tp the pad where I keep my trailer at home. I am having the electrician run four strand wire in case I want to upgrade to 50 amp service.

Why not do it once and be done with it? The 30A box and 50A box are not much difference in price at all! Also a 50A two pole breaker is not much more than a 30A single. Labor is no different for either.

Do it once and be done with it!

I am having a 30 amp service box installed next tp the pad where I keep my trailer at home. I am having the electrician run four strand wire in case I want to upgrade to 50 amp service.

last home I had a thirty amp box installed on car port.
On the Fifth Wheel it had only one and it was on most of summers.
I don't remember if TV would cause it to shed one of the air conditioners but the microwave would.
We ran them most, of the time mid summer as we had clothes and food etc always on board. The refrigerator was running too and especially when loading or unloading.
We had the box wired with one ought cable, which was overkill but the box or plug never got hot nor the distribution panel in the basement.

Johno02 wrote:
However, I did go back to 30A, mainly because at that time, the 50A wire alone would have cost me over three times as much as that needed for the 30A.

that is one reason that I sometimes recommend just adding another 30 amp wire of appropriate size so that you can eventually go to dual 30 amp breakers if desired. 60 amps is plenty of juice for routine at home use, assuming you aren't living in the RV in the desert.
bumpy

Johno02 wrote:
If you are going to have an electrician do it, and using new wiring, consider going ahead and running 50A and be done with it.

x2 - at least price having the 50 amp outlet put in.

If you are going to have an electrician do it, and using new wiring, consider going ahead and running 50A and be done with it. That is what I would have preferred to do when I ran my circuit for our 50A rig. However, I did go back to 30A, mainly because at that time, the 50A wire alone would have cost me over three times as much as that needed for the 30A. As we only use the supply for one AC sometimes, mostly just to keep the batteries charged when not in use. the 30A was plenty for us. And if we are doing anything with it parked there, the TV set gets to run sometimes.