20 Amp and A/C ?

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DebElliott

Member
Joined
Apr 28, 2017
Posts
13
I am new to these message boards and Im thankful I found you 'all.  I'm not sure if I can stay here for the summer if I can't prevent heat exhaustion.  Im in a class c conversion van.  late 80's model.  I'd like to know if I can run the air conditioner. 

  I'd like to know if using my a/c on 20 amp will do harm.  I disconnected the electric hot water heater which takes 7 amps.  I have the a/c dial all the way up to prevent cycling.  I can reduce the dorm fridge if necessary.  I have only my laptop and cable internet plugged in.  The A/C on the roof is fairly new but it's wired inside and plugged into one of the wall socket.  It has tripped the fuse box when I had the fridge and hot water heater going And the dial set low that caused cycling where it went dead as the compressor was coming on.    Should I try to use it or move where I can get 30 amps?   

Also,  I was told by kind people here that I can power the 8000 portable free standing a/'c on 15 amps.  It's an alternative to blowing circuits.  The wiring here is over 50 years old.    Kind regards, 
 
You can run an A/C on it's highest or lowest temp setting on a 20 amp circuit without a problem. Just don't run anything else. When you need hot water turn off the A/C and turn on the hot water heater for 15 minutes. Then take your shower, turn off the hot water heater and turn the A/C back on. But make sure the cord that runs from the RV to the power outlet is at least a 14 amp cord and not more than 25 feet.
 
I turned it on.  and when I did,  I heard a chirp from somewhere.  I've heard this before when turning it on.  It must be a surge of power to something.  I have been told by the park manager that I can't use the a/c on the 20 amp but i have no power meter unlike those on 30 amps.  should I turn off the fridge while cooling down?  Thank you sooo much for your help.  I'm feeling so much better under the cool.  ha.  I've had several bouts of heat exhaustion in recent years and have become sick easier and easier to heat. 
 
Can you run your fridge on propane?  If so, it won't have an appreciable effect on your electrical consumption.  If I have pretty much everything else off, I can run my A/C on my Honda EU2000i generator (though just barely) which outputs less than 20 amps.  But if I forget and leave my fridge on auto, it detects the current, tries to run on electric, and trips the circuit breaker.  Set on propane, it isn't a problem.

X2 on SeilerBird's caution on the power cord. I used a longer one once and it worked for awhile - but it got quite hot and fried itself.  I was lucky that's all that happened.
 
DebElliott said:
I turned it on.  and when I did,  I heard a chirp from somewhere.  I've heard this before when turning it on.  It must be a surge of power to something.  I have been told by the park manager that I can't use the a/c on the 20 amp but i have no power meter unlike those on 30 amps.  should I turn off the fridge while cooling down?  Thank you sooo much for your help.  I'm feeling so much better under the cool.  ha.  I've had several bouts of heat exhaustion in recent years and have become sick easier and easier to heat.
If the fridge is running on A/C then turn it off. If it is running on propane then no problem. Very few people live in a class B full time because of the problems you are running into. You need to upgrade to a C or an A and these problems will mostly disappear.
 
You're going to be pushing the capabilities of a 20 amp circuit running the air conditioner.  Besides turning everything off, you'll want to feel all of the connections including where you plug into park power for excessive heat after about an hour or so.  If anything is uncomfortably hot, you'll have to stop.

Air conditioners have a high starting surge - they draw lots and lots of power for a second or two when the compressor first starts.  Don't cycle the air conditioner on and off any more than you have to - if the compressor does stop, wait at least 3 minutes before you try restarting it.

The other problem is the voltage reaching the air conditioner.  Any time you draw current through a wire, you lose some voltage due to the wire's resistance.  A 50 year old 20 amp system might not be able to supply enough voltage to let the air conditioner run without damaging it.

Get a voltmeter and monitor the voltage inside your RV when the air conditioner runs.  Normal voltage is around 120 volts, if it gets down to 100-105 volts or less you're risking damage to the air conditioner.

I like the Kill-A-Watt meter.  It's also available at Home Depot.  You can just plug it into an outlet and use it's voltage and frequency functions, or you can plug an appliance into it, or your RV if it's using less than 15 amps, and see exactly how much power you're using.

It would be cheaper to move to a 30 amp site with it's larger wiring than having to replace a burned out air conditioner.
 
thank you.  This is what I was afraid of.    I should plan to move.    Great information from everyone.... 
 
20 amp is usually enough for the A/C, Converter, Televisions and perhaps the Fridge, You might wish to disable A/C when using Microwave

If you are using 30 or 50 amp cord with adapter,, Check the adapter often to make sure it does not overheat

if you are using a "Standard" extension cord (the kind with 15 amp plug and socket) make sure it is 12 ga.. That's about the best advice I can give.. Did it at least part time when this rig was new.
 
update,  while I was feeling fearful my friend and neighbor came to my door.  I told her about me having to leave,  she helped me understand alot of things.  the power cord  has almost no difference in temperature so she doesn't understand why i'm worried.  ha.  i cool it down in here and when i switch to fan i tun up the dial to the fridge.  it may be ok.  im  feeling optimistic. 
 
thanks John from detroit.    I have only the a/c going and the fridge on low.  I have battery for light.  when I turn it off I set up the fridge again.  I don't have tv or microwave.  I cook every thing on the outdoor fire.    No more hot water but it's already warm here.  I'm checking the wire every hour.  It's working very well.  I am not experienced with all this.  ha....  the neighbor saved my day when she explained everything to me and checked everything for me.  grin
 
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