What Size Wire 30amp

This website recommends #8 gauge wire:

https://www.icmag.com/modules/Tutorials/ElectricalSafety/1655.htm

No. 6.

Now would be the time to consider running wire that will handle 50 Amps, for future updates.

At 80 feet you can use 10/2, voltage drop will be 5V @30A. If your power is marginal you can go 8/2 and get 2V back but that's unlikely to make much of a difference.

Edit
Actually I forgot that you'll have the RV extension cord on the end, go at least 8/2.

gbopp wrote:
Now would be the time to consider running wire that will handle 50 Amps, for future updates.

Exactly. for a few $$ more, go with a larger gauge for possible future use.

Ron

Run what would be needed for a 50 amp outlet. A few dollars more--but a much longer term solution.

It's not really a few dollars more, it's a few dollars more per foot. So about $200 extra. I know I'll never have an RV big enough to need 50A service so for me it would be $200 wasted. Plus 4/0-4/0-4/0-2/0 outdoor cable is an absolute PITA to deal with so the install will be much more difficult than a simple 8/2 pull. The weight difference is also significant, 0.2 lb/ft vs 1.0 lb/ft.

Depends on:

- what the voltage is like at the panel in the house. Is it fairly stable near or at 120 volts or does it drop sometimes like when you and all your neighbors are running A/C units in their homes.

- what loads are you planning to run when at home? If the A/C sometimes, low voltage is a big concern. A/C units have an initial startup current of about 50-60 amps and it may have trouble starting if the wire is too small and too long and/or if the voltage gets too low (below 105), both will cause damage to the A/C.

- is the 80' direct line of sight or does it include the actual total length including ups & downs in walls and horizontal "bends" in the wire. When considering wire size and voltage drop, you should include the length of the #10 shore power cord too.

Not knowing all the details, I would say use #6 copper.

I installed a 30 amp recept. for our TT in the carport and used #8 for a total actual wire length of around 80-90' back to the panel, but we'd never use the A/C at home.

No reason why not to install wire for a 50 amp recept. but copper isn't cheap. Unless you think you might get a new 50 amp RV down the road and plan to run heavy loads in it (like 2 or 3 A/C units plus appliances) I'd just install what you need for now.

Another thing, and often overlooked, is the load calculation for existing house panel - assuming you are taking out a permit. You could find that by calculation a new RV receptacle in some cases is too much for an existing panel depending on size of house and what all the loads are. This would be more likely for a 50 amp recept. since you are talking about a load of 3600 watts vs 12,000 watts. If hiring an electrician, he/she would do the calc. for the permit.

My 30A outlet is about 75 feet from my bracker box. I ran 10/2 wire to it. I believe over 75 feet you should run 8/2 wire.

As far as wiring it for 50A. It's more than a few dollars. I priced it just for the heck of it and it would've been almost $200 more for something I'll never need. Even when I do get a 50A motor home I can run it off of a dog bone connector, 30-50A. I'm not looking to camp in my driveway just power up a few things and maybe run the A/C on hot days when packing. So 30A will be more than enough.