AC versus Generator question

Rusty2867 · July 09, 2016, 05:55 PM

My Minnie has a 11000 btu ac unit probably original 76 model Duotherm.I am looking at a 13500 btu Coleman Mach series of 2001 vintage,I can't find any info on what size generator it needs.Would my 2.8 Onan run it? Looking at specs on new ones it says 1560 running watts at normal cond. or 1960 at max

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Rickf1985 · July 09, 2016, 07:03 PM

It would run it, and nothing else. And the start up might be iffy.

M & J · July 09, 2016, 07:37 PM

Compressor start wattage is around 50% higher than run wattage.

Rusty2867 · July 09, 2016, 08:05 PM

I would need to be able to run lights and tv

Rusty2867 · July 09, 2016, 08:07 PM

I have a 4.0 BFA in my garage but it won't fit in the hole for generator and it needs brushes

Rickf1985 · July 10, 2016, 10:16 AM

I think the problem would be when the compressor kicks on, if the lights and TV are on then you could do damage to the compressor AND the TV. I think that is cutting it a bit too close.

Bnova · July 10, 2016, 11:29 AM

Quote from: Rusty2867 on July 09, 2016, 05:55 PM
My Minnie has a 11000 btu ac unit probably original 76 model Duotherm.I am looking at a 13500 btu Coleman Mach series of 2001 vintage,I can't find any info on what size generator it needs.Would my 2.8 Onan run it? Looking at specs on new ones it says 1560 running watts at normal cond. or 1960 at max

We have a 2.8 Onan on our Winnie and it runs the AC just fine, and can power the lights and other things at the same time. Although as Rick mentioned, you probably want to get the AC running before you have other lights and stuff turned on. The start up of the AC is pretty heavy, but once running we can run everything else at the same time for the most part.

We run a monitor that's plugged into one of our 110 outlets and can monitor voltage and freqs. So we do pay attention.

Froggy1936 · July 10, 2016, 02:04 PM

Just remember The AC compressor cycles off & on as it operates Frank

Rusty2867 · July 10, 2016, 03:11 PM

Quote from: Bnova on July 10, 2016, 11:29 AM
We have a 2.8 Onan on our Winnie and it runs the AC just fine, and can power the lights and other things at the same time. Although as Rick mentioned, you probably want to get the AC running before you have other lights and stuff turned on. The start up of the AC is pretty heavy, but once running we can run everything else at the same time for the most part.

We run a monitor that's plugged into one of our 110 outlets and can monitor voltage and freqs. So we do pay attention.

What size is your ac unit?

Bnova · July 12, 2016, 07:41 PM

Quote from: Froggy1936 on July 10, 2016, 02:04 PM
Just remember The AC compressor cycles off & on as it operates Frank

Yep, good point Frank. We are very conscious about the 110 stuff that's running while operating off the Gen.

Bnova · July 12, 2016, 07:43 PM

Quote from: Rusty2867 on July 10, 2016, 03:11 PM
What size is your ac unit?

Sorry, I don't have the books for it at home with me, but it is a Coleman 6700 series and I think it's a 13K BTU. Connected to a 20 amp CB. We're taking it out on a short trip this weekend. I'll take a look then.

Rusty2867 · July 13, 2016, 04:58 AM

Mine has a 11000 in it now and seems do do just fine on the 2.8 onan but I was looking at a 13500 to replace it everything I've been able to find says I need a 3500 generator but that's on Dometic site Coleman does not list a generator size sugestion

PwrWgnWalt · July 31, 2016, 02:54 AM

Here's how I figured out my electrical, and this may not work for you...

Given the wattages you state and using Ohm's Law,
1560 Watts divided by 110 volts (AC) = about 14 Amps.
1960 W / 110 VAC = 18 Amps.

The circuit your A/C is on should have a circuit breaker; what is it rated?
Mine was a 20 Amp.

What is your Generator's output rating (should state an amperage rating, at so-many volts)?

My genny (Onan BGA 5.0 kW) puts out plenty of current to run two A/C units, and lights, and all the rest.