15 amp adapter running the air conditioner

[awesomeman]

Is this possible? I was cleaning out the rv and was letting the generator run for an hour or so(do it once a month when rv not in use. Any ways I left the AC switch on when I shut it all down and plugged my 30 amp to the 15 amp adapter. I go outside about an hour later and the air is running no prob off the 15 amp adapter. Is this possible? Did I possibly mess up anything?

[valhalla360]

wolfe10 wrote:
Absolutely verify voltage immediately after generator starts-- needs to be at least 108 VAC.

The problem is not the 15 amps, it is the high likelihood of small-gauge wiring supplying that 15 amp outlet that causes an excessive voltage drop.

Put the 15amp to 30amp adapter right at the plug and most of the small gauge wiring issue goes away as you immediately transition to your 30amp cord. As long as the household wiring isn't substandard, should be fine.

[tatest]

If the A/C is the only major load and connections are good, there should be no problem. Your A/C is probably 10-12 amps running, and the higher starting loads are very short. The adapter will have no time to overheat. More often a problem will be long, too small, extension cords.

How long it can run on a 15 amp circuit depends on what else is on that circuit. The 15 amp circuit in my garage carries other loads (garage lighting, basement lighting, outdoor lighting, garage door opener) so I have to be careful about turning off everything else if I want to run the A/C while the RV is plugged in to the garage. A lot of garages these days have 20 amp utility circuits (as do kitchens) rather than 15 amp lighting circuits, so you may have more headroom than you think you do.

But I don't generally plug in at home to cool the RV. I do it for battery charging and precooling the fridge, so I'm usually drawing 5-8 amps for the RV, from a 15 amp adapter plugged into a 15 amp circuit.

[pnichols]

Another thing to consider in addition to a 15 amp circuit running a 13.5K RV air conditioner is the rating of the outlet receptacle used with the 15 amp circuit.

The receptacle on the 15 amp circuit we previously plugged the RV into when in storage in our backyard finally started getting hot and smoking last summer while it was powering the RV's A/C.

I replaced that burned up 15 amp rated receptacle with a 20 amp rated receptacle, even though the circuit was just only the standard 15 amp household circuit with it's 15 breaker. The 20 amp receptacle was a lot more ruggedly built than a 15 amp one ... so the heating problem should never occur again when powering the RV's air conditioner over the long term.

I have replaced several of our home's 15 amp wall receptacles with 20 amp ones. The 20 amp receptacles are only slightly more expensive than 15 amp receptacles. Of course a "20 amp rated receptacle" doesn't mean you have a "20 amp circuit" - because the home's circuit feeding the receptacle is still wired and fused to only handle 15 amps. What you get is a more rugged, and longer lasting receptacle for reliable use year after year.

[Larry-D]

I've done it with no problems and I've done it and melted the adapter.

[pianotuna]

I suggest jumping all the way to 50 amp.

awesomeman wrote:
either way Im having a 30 amp installed.......No more questions. Im getting used to all this adapter. Im sure its a smaller a/c unit so thats prob why it was able to run

[Matt_Colie]

Awes,

It is just fine...

I run my single 15.5K Carrier on a 15amp circuit all the time. Before that, I ran a 13.5K Coleman on the same circuit.

You have to be careful not to add any extra load to the circuit, but it should do it.

Matt

[awesomeman]

either way Im having a 30 amp installed.......No more questions. Im getting used to all this adapter. Im sure its a smaller a/c unit so thats prob why it was able to run

[wolfe10]

Absolutely verify voltage immediately after generator starts-- needs to be at least 108 VAC.

The problem is not the 15 amps, it is the high likelihood of small-gauge wiring supplying that 15 amp outlet that causes an excessive voltage drop.

[valhalla360]

mat60 wrote:
Isnt low voltage whats going to kill a A/C unit.

If you are drawing 10amps thru a 15amp circuit...doesn't hurt to check but if the generator is rated for it, no reason to expect low voltage.

[mat60]

Isnt low voltage whats going to kill a A/C unit.

[valhalla360]

It's fine. Over 15amp is where the breaker may cut out. Typical RV air/con units run 9-12amps except on startup where they pull 2-3 times as much for a second or so while the compressor spins up to speed.

Breakers don't cut out instantly. The speed varies based on how much over the limit you are at 15.1amps, it may take a several minutes to pop. At 100amps it may take miliseconds. As long as it gets over the hump, the breaker is unlikely to pop. (of course, there is a bit of variability between identical breakers both out of the box and depending on how they have aged, so don't count on exact down to the 1/10th of an amp).

Assuming there is nothing else sketchy going on and the connection isn't getting hot, you are fine.

[pianotuna]

What was the voltage?

[Old-Biscuit]

Obviously it is OK cause A/C Unit started/ran and no magic smoke got out OR did 15A Circuit Breaker trip (which is what would have happened if too much amperage had been pulled on that circuit)

[Isaac-1]

It should be fine as long as the 15 amp outlet is wired properly and is in good condition. If it is an old outlet with corrosion in it, then it may overheat with the 12-13 amps worth of load that may be found from an RV air conditioner. This of course assumes there are no other loads present.