20 amp vs 30 amp

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steelmooch

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Aug 5, 2010
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280
Hello all...

In our first full season of camping, we became accustomed to 30 amp service in our area and in a 3,000 mile PA-to-FL trip that we really enjoyed.  :)

Looking into a 20-amp site for the Spring...I know that I could not run my rooftop A/C in our 21' TT. 

Besides that, would our small refrigerator be OK?  Could we run the fridge, leave the water pump to "on", and not be super-stingy with the lights as well? 

Thanks! 
 
Sure, you can run the AC on 20 amp service. You'll want to run the water heater on propane while it's on though.

We attend a rally every spring at a fairgrounds with 20 amp service, and have occasionally needed the AC. No problem doing that while the fridge is running.

Remember, lighting and the water pump are 12 volt loads. Although they are powered through the converter, the current draw is minimal.
 
I spent a week last summer in my 30A motorhome plugged into a 20A receptacle. I found that I could run everything, including the AC unit, as long as I didn't try to run the electric water heater, and the AC at the same time. After I tripped the breaker, I switched the water heater to LP and never had another problem. I ran a coffee pot (Mister Coffee) and microwave together for breakfast with no problem. Of course the AC didn't come on till later in the morning, after breakfast was over. You'll be OK, and if you do trip the breaker, just reset it and shut something down. Water pumps and lights are 12V and will be OK.
 
Some a/c units will start ok on a 20A circuit, while others will not. The start-up surge current is a chancy thing on 20A. If it does get started, it will run ok..

Most everything else will be fine as long as the a/c is not running, including the fridge in either electric or gas mode. Water heater should be on LP gas, as Happy suggests.  That's a 12A load all by itself if on electric.

 
I run my trailer AC all the time while plugged into my house 20 amp circuit.  However, if I forget the AC is running and turn on my 120 VAC vacuum cleaner after a minute or so the house circuit breaker pops.  I just reset the breaker and try to remember to just run one electrical appliance at a time.  With the AC running my volt meter, that plugs into any outlet in the trailer, reads 110+ VAC.

I have used 20 amp supplies at fairgrounds.  The AC would always run fine and we would run the other appliances on propane.  If we want to run a toaster or coffee pot, etc. we turn the AC to fan or off.  However, when on 20 amps I always monitor my plugin volt meter, it plugs into any outlet in the trailer.  If I run into a situation where my voltage drops to 105 VAC or below I do not run the AC at all, but i may run the fan.  This often happens during breakfest and dinner times and on very hot days during times when everyone in their unit and running their AC's.  It is rare that we see 20 amp voltages that low however.
 
If plugged into a 20 amp outlet is a good idea to use a pigtail adapter or even a short 1-2 ft heavy duty 3 way splitter cord as old outlets have a tendency to overhead and char power cords at heavy loads before the breaker trips.  It is better to loose a $10-$15 short pigtail than an expensive 30+ ft heavy duty cord.
 
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