What Size Wire 30amp

Westcoasting wrote:
I would use #8 aluminum and save a few bucks over #10 copper.

Aluminum wire has had expansion/contraction issues in the past. there have been reports of loose connections due to it. and even some fires from loose connections that build up heat. I have aluminum service coming into my house and I need to check the connections regularly for tightness.

Best stick to copper.

wanderingbob wrote:
500 feet of # 6 wire is $206 at my Lowes . it will run 50 amps for 125 feet with a 3% voltage drop . Fifty amp should only cost less than fifty dollars more . For 30 amp at eighty feet # 10 will do fine .

You`ll need 4 different color of wires. so one 500 foot roll will work.

Thanks much for all the info.

I would use #8 aluminum and save a few bucks over #10 copper.

Important thing is to adequately power any sensitive, power hungry devices (Air conditioners, other large draw motors, 12V converter) and be able to maybe power them together. AWG #10 meets the ampacity of 30 amps of current requirement. If having a run of wire close to 100', AWG #8 would be a much better choice.

Rationale for installing a 50 amp pedestal has a lot of merit but costs often overrule best possible solutions. With 50 amp service and the larger wire (also multiple outlets), you would never suffer a loss of power.

Here's a tip for those wanting larger wire: shop a local electrical surplus reseller. Large metro areas typically have at least one reseller in the area. I bought single conductor AWG 6 with a very good jacket for $.50/ft, recently.

FWIW, I used two lengths of this to power a 50 amp subpanel, the ground terminated at the subpanel location. The subpanel powers a welder receptacle, my 50 amp RV receptacle, and 4 x 15 amp 120V receptacles. Yes, I'm kind of cheating on the total ampacity, but none are all used at the same time and I'm using a larger load center box.

500 feet of # 6 wire is $206 at my Lowes . it will run 50 amps for 125 feet with a 3% voltage drop . Fifty amp should only cost less than fifty dollars more . For 30 amp at eighty feet # 10 will do fine .

I'm at 100' and 10awg wire.
At full load I get about a 2~3 volt drop which ends up being about 118VAC.
We'll be parking a new TT farther away and for the time being, I'll be running both 25' and 50' RV (10awg) extension cords.
Should be interesting to see how that works..

50 Amp RV is 4 wire split phase (2 120 hots + neutral + gnd). 30 amp RV is 3 wires single phase (120V hot + neutral + GND). So the cost for 50 amp is quite a bit more. You also need to be careful to make sure it is legal/safe for you to add more circuits to your panel, it may already be maxed out. You need to consider if you have any open space in your neutral and ground bus bars for heavy wire too.

I wouldn't do any heavier than #6 CU because chances are the 30A breaker and socket lugs won't accept anything heavier anyway.

I ran a 50/30/20A RV panel with integral breakers for my house but that worked out for me because I replaced an old hot tub junction box that already had 50A/240V run to it with #4 CU.

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.

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.