What Size Wire 30amp
I would like to put a 30 amp RV plug on my garage. The service pole is about 80 feet from the garage. I was wondering was size wire I will need to support 30 amp service.
Forum Discussion
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.
- 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.
