I am trying to find out how many kilowatt hours a 4 ton 1.5 hp a/c unit uses and how much is the startup draw.

Question

I need to know what the average power draw is when the AC unit first comes one.

Answer 1

Why?

Take an amp draw on startup.

The draw will be higher when under a load and having some start assist will make a difference.

It's only for a short period.

Answer 2

I have to agree with"gizmo" "why" to check startup draw you would put an amp meter on one of the 120 volt lines to the unit and then turn the unit on if you are quick you will see the amp draw peak for a mere second and then it will drop back to it's running amps, if you can get an amp meter that will lock it's self at that highest startup amp and you can get a better idea of what it is instead of guessing at it after start up.

How much a/c does it use depends on a lot of circumstances is the outside unit fins clean or fouled,they need to be as clean as possible so that it can draw air over the coil and get a good transfer of liquid freon to a gas freon, this also applies to the evaporator side of the system that is located in the plenum of the furnace.

Outside air temp has a lot to do with the load on the unit, is the sun beating directly on the unit, can it be put in a shady area if it is ever moved .

There is a lot physics going in that unit in a very short time frame, so it's amp draw is based on a lot of factors.

Welcome to A.C.101.

Answer 3

Get an ampprobe and meter it.

Answer 4

go to this web site and it gives you cost to run equipment