Originally Posted by camtaysan2
Howdy, Thanks for your response. I am using an 20A outlet from the house and using a heavy duty extension cord and the campers power cord. I guess I never tried the microwave and A/C together at home before. We are going camping later this month and I will try it at a dedicated 30A circuit there. I guess i'll have to wait until then unless you think there might be something else.
Nope, my money is now on low AC voltage due to line loss during power up of the microwave. If you buy a 120VAC plug in volt meter (cheap) you can actually watch that voltage drop below 90 volts when the AC compressor or Microwave fires up.
You are getting the full 120 VAC with low load, but try to pull a large bunch of amps through a heavy duty extension cord and the voltage loss in through the cord will cause the voltage to plummet.
A Voltage stabilizer like the one pictured will help by converting amps to volts to keep your line voltage up under heavy usage. The downside is that it increases amp draw from your source to provide the correct voltage at your camper.
Microwave Load 1200 watts (120 volts x 10 amps)
Air Conditioning Load 1200 watts (120 volts x 10 amps)
Load in camper: 2400 watts (120 volts x 20 amps)
Load at outlet 20 amps - circuit breaker can hold the load.
Line loss due to trying to cram 20 amps through that long skinny extension cord drops voltage to 100 volts.
Air Conditioner "lugs" and may burn itself up.
Microwave magnetron may not fire at all or might burn itself up.
Putting the stabilizer in the circuit:
The 100 volt condition puts the Franks into "High Boost" and boosts the voltage to 117 volts. Air Conditioner is happy; microwave is happy; Fuse panel NOT happy. The franks will consume an additional 4 amps to make that voltage and your house fuse will blow.
If you intend to continue using an extension cord get a high quality 30 amp one. Plug into a circuit rated at 30 amps. ALWAYS check voltage available at the outlet UNDER LOAD. Carry a power stabilizer in your bag of tricks for when your spot is at the end of the campground's circuit run and everyone is using their air conditioners.
I have been at campgrounds and was only getting 105 volts from the pedestal BEFORE I plugged in. My Franks gets unpacked and hooked up before the camper is.
I HIGHLY recommend a 30 amp rated extension cord to limit line loss.