Can a 30amp A/C run on 20 amps?
One of my sons bought a travel trailer to use as 'seasonal' for him and his family. Dealer will deliver and set it up. One a/c unit. Only NOW....does he tell me his site is 20 amp....with a "promise"...
Forum Discussion
Hi,
Depends on the distance from the campsite to the main meter.
At the main meter, there probably is 118 - 120 volts. 300' away with #12 wire, then the voltage drop with a 12 amp A/C load on that small wire, there might only be 105- 108 volts. So it really depends on the wire size and distance.
I would suggest a voltage booster. You will probably need it, or require it. Even a 12 volt boost might not be enough on a warm day.
My hope is that when they upgrade, they will put in #8 or larger wires! That is great for 30 amps at about 200' from the main meter, but any further, the resistance in the wire means you will still have low voltage. . .
I lived about 300' from the ranch house, and could count on a 12 volt drop when I ran my A/C unit. And they did have #8 wire from the house to the pump house, and I was plugged in to the pump house. I have a 12 volt booster, and used it all summer, but plugged in my refrigerator to the non-boosted receptacle, so I did not want it running on 132 volts when I was not running the A/C unit.
You MUST have a volt meter that can stay plugged in all the time. Look for a Kil-a-watt on E-bay for about $25. Plug in to a living room receptacle in the RV. When voltage drops below 105, then shut off the A/C unit. If voltage pops back up to 116 then you will know that you have a constant 11 or 12 (whatever it pops up by) voltage drop, and know that you will require a voltage booster. Without a volt meter, you are risking damage to the A/C unit. Your voltage will be very marginal - especially with #12 wire to each site.
#10 wire has a max fuse size of 30 amps, so likely they installed #12 wire and have 20 amp circuit breakers for each site.
Larger RV parks with 50 amp services use relatively huge wire - say #0 wire and then protect 10 - 12 sites with a 150 amp circuit breaker. #2 wire is good for 100 amps, and is almost the diameter of a pinky finger. #0 is larger than that! With #0 wire, there is practically no voltage drop in 100' and only 1-3 volts with a 300' long run. However the wire is a little over $2 per foot, and likely out of the budget for a small RV park that is just starting out. That is why they used #12 wire to start out with, and you have a huge voltage drop.
Good luck!
Fred.
Depends on the distance from the campsite to the main meter.
At the main meter, there probably is 118 - 120 volts. 300' away with #12 wire, then the voltage drop with a 12 amp A/C load on that small wire, there might only be 105- 108 volts. So it really depends on the wire size and distance.
I would suggest a voltage booster. You will probably need it, or require it. Even a 12 volt boost might not be enough on a warm day.
My hope is that when they upgrade, they will put in #8 or larger wires! That is great for 30 amps at about 200' from the main meter, but any further, the resistance in the wire means you will still have low voltage. . .
I lived about 300' from the ranch house, and could count on a 12 volt drop when I ran my A/C unit. And they did have #8 wire from the house to the pump house, and I was plugged in to the pump house. I have a 12 volt booster, and used it all summer, but plugged in my refrigerator to the non-boosted receptacle, so I did not want it running on 132 volts when I was not running the A/C unit.
You MUST have a volt meter that can stay plugged in all the time. Look for a Kil-a-watt on E-bay for about $25. Plug in to a living room receptacle in the RV. When voltage drops below 105, then shut off the A/C unit. If voltage pops back up to 116 then you will know that you have a constant 11 or 12 (whatever it pops up by) voltage drop, and know that you will require a voltage booster. Without a volt meter, you are risking damage to the A/C unit. Your voltage will be very marginal - especially with #12 wire to each site.
#10 wire has a max fuse size of 30 amps, so likely they installed #12 wire and have 20 amp circuit breakers for each site.
Larger RV parks with 50 amp services use relatively huge wire - say #0 wire and then protect 10 - 12 sites with a 150 amp circuit breaker. #2 wire is good for 100 amps, and is almost the diameter of a pinky finger. #0 is larger than that! With #0 wire, there is practically no voltage drop in 100' and only 1-3 volts with a 300' long run. However the wire is a little over $2 per foot, and likely out of the budget for a small RV park that is just starting out. That is why they used #12 wire to start out with, and you have a huge voltage drop.
Good luck!
Fred.
