15KW A/C amp draw?

bills · 07-10-2013, 06:59 AM

I'm not sure that this is the right place to post this, but here goes anyway.
Can anyone give me the amperage draw of a 15KW A/C unit both at "startup" and "running" modes?
Thanks
Bill

Witch Doctor · 07-10-2013, 07:19 AM

The running full load amps will change depending on conditions should be around 12 to full loaded amps at 15 running. Your start up amps will pull around 22 amps from the start wind then it will drop right down. ( your 20 amp breaker will hold it for that short period). That is why some people put on whats called a hard start capacitors. It stores power then on start up it will assist in getting you out of the start wind faster. I think that your locked rotor amp is like 45 or 50 would have to check. that is what will trip your breaker if your compressor try's to start before the high and low side equalize and it will trip the 20 amp breaker in your panel. These are pretty close est. without me looking at the name plate on the ac unit.

**Herk7769** · 07-10-2013, 07:38 AM

I have a 15K Coleman Mach III.

The running and start up amps are voltage dependent. As you can see from the plate on mine, all readings are based on 115 volts AC. The lower the incoming voltage; the higher the amps.

The incoming voltage will drop under load if the campground has aluminum service wires to some very low voltages and can "recover" to more normal voltages when the compressor and fan come up to speed.

My compressor draws about 12 amps running (RLA) and the fan motor uses an additional (about) 3 amps for a total of 15 amps running. While locked rotor amps (LRA) can hit 58 instantaneous amps, mine has drawn over 30 amps starting if the voltage is below 110 volts before I made some modifications.

With a hard start capacitor and 5 second fan delay relay, the start up amperage now does not peak above 25 amps for about 1 second.

To be UL rated, the start up current should not exceed 1.56 times the RLA for the compressor (18.72 amps) and 5.3 amps for the Fan for a total of 24 amps.
Of course this is at 115 volts. Again, lower voltages will make these numbers higher and very low voltages will blow circuit protection if the compressor stalls.

Witch Doctor · 07-10-2013, 08:04 AM

hERK, JUST WONDERING HOW OLD IS YOUR UNIT i SEE ON YOUR NAME PLATE THAT IT SHOWS R-22 FREON ?

OldCoot · 07-10-2013, 08:25 AM

Quote:

Originally Posted by gljurczyk

hERK, JUST WONDERING HOW OLD IS YOUR UNIT i SEE ON YOUR NAME PLATE THAT IT SHOWS R-22 FREON ?

According to his signature, he has a 2010.

**Herk7769** · 07-10-2013, 08:32 AM

Factory installed in June 2009 (2010 model year).

Next time I am up there I will try to see if there is a MFR date. (Grrr that is why I took the photos) Bummer it is not on the sticker.

Big Vic · 07-10-2013, 08:46 AM

After it starts up, my 15K A/C draws 12 amps for compressor and 3 amps for fan. I always manually put on the fan first, wait a few seconds, and then start the compressor. Seems to start easier that way.

**Herk7769** · 07-10-2013, 03:08 PM

Quote:

Originally Posted by Big Vic

After it starts up, my 15K A/C draws 12 amps for compressor and 3 amps for fan. I always manually put on the fan first, wait a few seconds, and then start the compressor. Seems to start easier that way.

Doesn't the fan stop when you switch from fan to cool?
Mine does...

TURBS · 07-10-2013, 03:52 PM

Quote:

Originally Posted by Big Vic

After it starts up, my 15K A/C draws 12 amps for compressor and 3 amps for fan. I always manually put on the fan first, wait a few seconds, and then start the compressor. Seems to start easier that way.

My fan delay mod would prevent you from having to get up and do that

With delay box the a/c compresser kicks on then depending on how many seconds you set the delay for then the fan will kick on .

http://www.forestriverforums.com/for...mod-20541.html

Turbs

VinceU · 07-10-2013, 06:01 PM

Quote:

Originally Posted by bills

I'm not sure that this is the right place to post this, but here goes anyway.
Can anyone give me the amperage draw of a 15KW A/C unit both at "startup" and "running" modes?
Thanks
Bill

If you take any watt load (15K is converted to15,000) and divide by voltage ex: 120 you'll receive an answer in amps.

**Herk7769** · 07-10-2013, 06:12 PM

Quote:

Originally Posted by VinceU

If you take any watt load (15K is converted to15,000) and divide by voltage ex: 120 you'll receive an answer in amps.

125 amps?

I think the 15,000 refers to BTUs of cooling.

bills · 07-10-2013, 06:13 PM

Thanks for clearing that up. I came up with 125 amps also and knew something wasn't right - just didn't know what the problem was.

VinceU · 07-10-2013, 06:19 PM

Quote:

Originally Posted by bills

Thanks for clearing that up. I came up with 125 amps also and knew something wasn't right - just didn't know what the problem was.

Sorry bout that, keyboard eraser is missing sides I was watching the evening news. Thanks Herk!

**Herk7769** · 07-10-2013, 06:20 PM

Quote:

Originally Posted by bills

Thanks for clearing that up. I came up with 125 amps also and knew something wasn't right - just didn't know what the problem was.

Vince is outstanding and always factual and correct. Today must be a day for "mulligans" as I pulled a bonehead mistake earlier today.

Big Vic · 07-11-2013, 02:50 PM

After it starts up, my 15K A/C draws 12 amps for compressor and 3 amps for fan. I always manually put on the fan first, wait a few seconds, and then start the compressor. Seems to start easier that way.
Doesn't the fan stop when you switch from fan to cool?
Mine does...
_________
Nope...the fan has its own switch (hi/lo) and runs whether the A/C is on or not.

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