20 amp Circuit & A/C?
We just bought a new-to-us Funfinder Travel Trailer and need to check out the A/C. Unfortunately I don't have a 30amp receptacle at the house. Does anyone know how long I can run the A/C on 15/20 am...
Forum Discussion
Advice of 3 posters is right. It's the voltage that is very important. The general rule of thumb is anything below 105 volts is bad and time to shut everything off in your RV. A SurgeGuard protector shuts off at 103 volts. The last AC manual I looked at, a Coleman, said anything below 103.5 volts can damage the AC unit.
Two things can lead to low voltage at your RV. One is the supply voltage in your house. That will be a nominal 120 volts but can vary depending on the time of day, part of the country you are in and temp. out (ie., lots of AC units on). The second is the length and wire gauge of the extension cord (which maybe is what OP asked?). An AC unit has a high startup current so even if the running voltage is okay, you are better off with a heavy duty extension cord, meaning higher gauge wire, not more substantial jacket on the cable. If the no load voltage at your RV with a smaller gauge and long extension cord *seems* okay, it can struggle to start and be damaging. A minimum #14 gauge cord is better but a #12 gauge is best. For longer runs like say 100' overall, go with #12. You can easily have 50'+ of #14 inside your house.
If your AC is still struggling, there's always the hard-start capacitor mod. that would help. Not expensive and a good idea anyway for longer comp. life. Info. here: Hard start capacitor mod.
RoyB, the prongs on that 30 amp plug are damaged from plugging the cord in live all the time. When you plug in live, the converter causes a momentary inrush current that causes a snap, crackle and pop when you plug in and you will see a flash in the dark. That pits the metal and in the long run causes high enough resistance to overheat the plug or receptacle and cause damage and even a fire. NEVER plug your RV cord live into a receptacle or extension cord. At home, you'll need to shut the breaker off.
Two things can lead to low voltage at your RV. One is the supply voltage in your house. That will be a nominal 120 volts but can vary depending on the time of day, part of the country you are in and temp. out (ie., lots of AC units on). The second is the length and wire gauge of the extension cord (which maybe is what OP asked?). An AC unit has a high startup current so even if the running voltage is okay, you are better off with a heavy duty extension cord, meaning higher gauge wire, not more substantial jacket on the cable. If the no load voltage at your RV with a smaller gauge and long extension cord *seems* okay, it can struggle to start and be damaging. A minimum #14 gauge cord is better but a #12 gauge is best. For longer runs like say 100' overall, go with #12. You can easily have 50'+ of #14 inside your house.
If your AC is still struggling, there's always the hard-start capacitor mod. that would help. Not expensive and a good idea anyway for longer comp. life. Info. here: Hard start capacitor mod.
RoyB, the prongs on that 30 amp plug are damaged from plugging the cord in live all the time. When you plug in live, the converter causes a momentary inrush current that causes a snap, crackle and pop when you plug in and you will see a flash in the dark. That pits the metal and in the long run causes high enough resistance to overheat the plug or receptacle and cause damage and even a fire. NEVER plug your RV cord live into a receptacle or extension cord. At home, you'll need to shut the breaker off.
