Does it kill an A/C to run it off a generator?

the thing i do is run the generator in the morning for breakfast and charging

IF I'm going to need A/C later, i let it charge long enough that the converter will not be a big load
i always run FAN ONLY for about 5~10 minutes before switching to cool
then i usually leave the A/C on full/max cool.. ( not cycling the compressor )
lot easier on the genny and the A/C if its NOT cycling

usually if i need A/C i don't need it cycling on-off

This hasn't been mentioned and may not be applicable, but a hard start cap reduced the startup voltage drop by at least 8 volts on my Coleman MachIII.

valhalla360 wrote:

MrWizard wrote:
to answer the OP question
No.. as along as the generator is big enough (enough KW), it is going to maintain voltage and NOT hurt the A/C

if the generator is too small, either the A/C will stall or the generator will overload/trip breaker/stall engine

the MOST often occurrence of A/C damage is extensive runtime with low voltage shore power, something that does NOT "naturally happen" when using a generator
a generator under so much load it has "low voltage" is going to "fail" in some manner, as noted above

That was my thought. 1/2 sec of high amperage isn't likely to burn out anything. As long as it quickly recovers and holds a good voltage, there shouldn't be a problem.

x3
I have a PI EMS and a Kill-A-Watt for this purpose (even on shore power). Most modern AC are rated at 115V. with the 10% rule that means the AC will be fine down to 104V. The PI will shut down power to the coach if it drops below 104. The PI has lifetime warranty and great protection. The Kill-A-Watt is for my sanity. When it gets below 108, I get nervous and start shutting down 120v systems.

This is good news. The nice thing about my Yamaha is that other than brief times of bogging down, it either puts out 120 volts (+ or - a couple) or 0 volts (i.e. it overloaded and needs to be restarted.)

What I might do is turn off the circuit breaker on the charger the first time I get the generator started, then once the compressor is on, turn it back on. Or use an external Schumacher that has some multi-stage capability without using the internal converter.

This is very good advice. The last thing I want to do is burn out either device... in the Texas spring and summer, it is the difference between a nice campout versus an uninhabitable TT.

MrWizard wrote:
to answer the OP question
No.. as along as the generator is big enough (enough KW), it is going to maintain voltage and NOT hurt the A/C

if the generator is too small, either the A/C will stall or the generator will overload/trip breaker/stall engine

the MOST often occurrence of A/C damage is extensive runtime with low voltage shore power, something that does NOT "naturally happen" when using a generator
a generator under so much load it has "low voltage" is going to "fail" in some manner, as noted above

That was my thought. 1/2 sec of high amperage isn't likely to burn out anything. As long as it quickly recovers and holds a good voltage, there shouldn't be a problem.

I have a 4300 watt Subaru inverter and I never have any problems running AC or anything else. I put a current meter on my gen and with the AC running the whole things draws between 8 and 9 amps.

to answer the OP question
No.. as along as the generator is big enough (enough KW), it is going to maintain voltage and NOT hurt the A/C

if the generator is too small, either the A/C will stall or the generator will overload/trip breaker/stall engine

the MOST often occurrence of A/C damage is extensive runtime with low voltage shore power, something that does NOT "naturally happen" when using a generator
a generator under so much load it has "low voltage" is going to "fail" in some manner, as noted above

mlts22 wrote:
I forgot to add that when testing one of my outlets as per a DMM, I get 120 VAC when the A/C is on, and 122 VAC when the A/C is off. There is a brief transition, but I've seen the DMM hit ~105 or so for a fraction of a second, but not lower.

Subsequent compressor starts/stops don't bog the compressor nor drop the voltage under 115, until the next day.

Those voltages are good. As someone else suggested you might let the Genny run your converter for 30 minutes or so before turning on the AirCon.

Old-Biscuit wrote:
A/C compressor (and fan motor) are drawing voltage down upon start faster than generator voltage regulator can respond.
Lower voltage=higher amp draw=shortened life span

Get a simple plug in voltmeter...plug it into an outlet where it can easily be seen and check the voltage when starting the A/C using generator.

Most 'power protection' (surge guards) devices trip on low voltage at 102V but that is just way too low for me.
I don't like running my A/C when voltage is below 108V AC for any length of time.

Plug in voltmeter.....

These type Voltmeters have an error of as much as 20%. So, for this type test, will NOT be close to accurate. They also do NOT like the voltage/Frequency of APU's. I advise people the only thing they are good for is letting you know, that you DO have 120 current in the RV, but they will NOT give you an accurate reading of that voltage. Spend a few bucks more and get the LED plug in Voltage tester. They are much more accurate. Doug

plug in an in line veltage meter (about $20.00). MOst 120 volt AC appliances operate just fine on 120 volts plus or minus 10%. If the genny will hold 107 volts or more it should do no harm. Unless you MEASURE the voltage you're just guessing. On a related matter though, MOST generator manufacturers do NOT recommend running their generators at full draw for long periods of time. The harm in that case is to the generator, not the AC.