120 VOLT INPUT

Thanks for the prompt replies. I will try a shorter/larger extension cord and trip all breakers but a/c and see what happens! Hate having to run the generator when the "Beast" is in our driveway and we're working inside. Of course, that is infinitely better than frying the whole rig!

By theory, the code will allow you to have a no more then a 3% voltage drop at an outside receptacle and if you plug in your RV to run your AC, it states that it will allow 5% or less at the AC unit. This is the voltage difference from your house panel to the load.

This is a recommendation and not an absolute. If it was than we would not have low voltage at half the parks in the US. However I do agree that a 20 Amp circuit will easily hold one air unit even with the refer on electric, but it is always a good idea to put it on gas to give you a little room.

Sam

Dave H M wrote:
so common, I am holding my breadth on the OP answer as to what if any extension cord is being used? :h

Lets just hope its not one of those flat brown or white ones from the Dollar Store.
Neil

Dave H M wrote:
so common, I am holding my breadth on the OP answer as to what if any extension cord is being used? :h

Yeah. Hope he's reading this.

FYI I've seen terminations/connections give off more than 100 watts of heat. For a while.

The "problems" boil down to this...

In a code approved home a connection of an appliance directly to a receptacle WITHOUT ADAPTER means the device will have correct power potential made available to it. Overcurrent will trip the home's breaker BEFORE voltage sags to the point of causing a problem.

I have to stop and wonder about the PERCENTAGE of folks who know they are on thin ice and decide to risk it anyway. An individual has how many (?) an unlimited number of ways to ask and check if he is doing a project correctly before he decides how to go about it. The magic word is before.

I wonder.............

What these folks do for a living

so common, I am holding my breadth on the OP answer as to what if any extension cord is being used? :h

The electrical codes are guide lines, they’re made from electrical theory and if you don’t understand the electrical theory, then you won’t understand the code.

Very simply put the length of copper wire, gauge, insulation and wiring installation method you use to calculate wires current rating. Voltage drop is giving off in the form of heat along the conductor and reduces the voltage supplied to the load at the end of the wire. The voltage drop of a wire is proportional to the current through it because the resistance of the wire in mostly constant. Ohm’s Law states that Voltage Drop = amps x resistance (V=IR). So the longer the wire, the resistance increases and so does the Voltage drop. And a motor is designed to run at a certain voltage and if the voltage is reduced by voltage drop, the motor current will increase. This will increase the voltage drop, although nonlinear, hopefully the motor protection in the AC unit protects it

By theory, the code will allow you to have a no more then a 3% voltage drop at an outside receptacle and if you plug in your RV to run your AC, it states that it will allow 5% or less at the AC unit. This is the voltage difference from your house panel to the load.

My point is that a common house 14 gauge wire is rated for 13.5 amps with an AC load (motor) up to 50 feet. At my house, my power panel is 50 feet from my outside receptacle and in my RV the AC unit is on the roof and over 20 feet from the panel in the RV. So it doesn’t matter what gauge extension cord I use from the house to the trailer. The code tells me I can’t, the electrical math tells me that I don’t want to run my RV AC unit at 101 volts and ruin it.

FYI:
A 50 foot 14 gauge extension cord at 13.5 amps will give off 46 watts of heat due to voltage drop.
(P = I x I x R).

Great presentation ROY B!

There is more to this story than plugging in a trailer "correctly" to a 20-amp circuit and not having the air conditioner work. Correctly means, using an extension cord rated correctly, and not trying to run all the appliances at the same time INCLUDING those that may be connected to the household 20 amp circuit independently.

Do yourself a favor & go ahead & get a 30 amp hook up installed, or else you'll end up under powering the A/C & burn it up.
Theres some things you can get by with, doing what you got to do to get by, but dealing with electricity not one of them.
Neil

beemerphile1 wrote:
Your air conditioner probably draws around 12-13 amps. There is no reason a 20 amp circuit won't allow it to operate. Every RV I have had was able to run the air on a 15 or 20 amp circuit.

Agreed, IF:

Absolutely everything else is turned off-- things like refrigerator on 120 VAC, water heater 120 VAC, converter or charger unless batteries are already at full charge.

AND, no long and/or under-gauge extension cords.

AND, all prongs are clean (shiny metal) and tight