Newbie-type question about power supply at home

[profdant139]

Our trailer is in the driveway, and we are getting ready to have some remodeling work done on our house. We want to use the trailer as a "lifeboat" during construction. We have never done this during the summer (usually we are traveling!), so we will need the air conditioner.

My concern is that the garage (where we will be plugging in the trailer) is only on a 20 amp circuit breaker. I don't want to starve the trailer for power and possibly damage the air conditioner.

So here is my question -- if we have an electrician come out and install a 30 amp breaker on our panel, will that be adequate to allow us to plug the trailer into the garage outlet and run the air conditioner? (We will be using a very heavy duty extension cord.) Or do we also have to change the wiring and the outlets in the garage?

Thank you in advance for your expert commentary!

[profdant139]

LittleBill, that is a good observation -- the breaker in the trailer is only 20 amp, and it has never popped.

Now for a really dumb question -- I have a multimeter, but how do I check the voltage of the outlet while the air conditioner is running? It is my amateur understanding that I can just stick the probes into the open slots of the outlet. But does that measure the voltage of the socket that is feeding the air conditioner?

And since I am asking dumb questions, is there a positive or negative slot in the outlet?

Thanks again for your help.

[LittleBill]

or put a meter on the outlet, considering the ac runs on a 20 amp breaker, you will be close to max, but if u want to manage loads you would prolly be fine.

just need to check the voltage when running. anything under 108 is no good.

[profdant139]

Thanks for the fast answers!!! I now know what to tell the electrician. Very helpful.

[enblethen]

Quick answer is no! Receptacle will not last, wire off existing 20 amp is too small.
If you are having electrician come out, have him install a thrity amp breaker, a 120 volt three wire (white, black and bare ground) and a thirty amp NEMA 30TT receptacle.
Make sure he knows that it is a 120 volt receptacle.

[maddog348]

Did that years ago. 30A breaker on panel. Great for working in MH during the summer ~~ OR ~~ when unexpected O/Nite company arrives. Had dedicated 30A Outlet installed outside Garage close to MH.


JM2¢ ~~ YMMV

[PNW_Steve]

To add a 30 or 50 amps hookup you will need to add a breaker, appropriately sized wire and receptical.

The cost difference between 30 & 50amp should not be that much.

If you need one roof air then a 30 amps should be adequate. If you need two roof airs or have other large loads you want to look at going with the 50 amp.