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Topic: Generator to run A/C

Posted By: CR13 on 08/09/11 07:34pm

What size generator do I need to run a 13500 A/C and what do I need to run a 15000 A/C?

Posted By: past-MIdirector on 08/09/11 08:23pm

Running Amps is about the same for both. I would go any small than a 3000 watt generator. At 3000 the generator will not be running at full load the whole time.

Posted By: DrBaker on 08/09/11 08:49pm

For 13.5 I like the Yamaha 2400. For 15k I like 2 2000 units in parallel such as Champion, Yamaha, or Honda.

A 3000 watt is also good for a 15k, but weight and size cause issues for some.

2011 Chevy 2500HD CC/SB 4x4 Victory Red
2003 Crossroads Cruiser CF27RL
Champion Screamer, Reese 16k, and a Blue Status Symbol

Posted By: TexasTiger220 on 08/09/11 08:58pm

my recommendation...


2013 Chevrolet Silverado 2500 HD Crew Cab Z71 6.6L Duramax
2013 Keystone Hideout 29BHS w/ Outdoor Kitchen
Geaux Tigers!

Posted By: ~DJ~ on 08/10/11 07:19am

Minimum of Honda 3000 if you are camping at much elevation, or plan to. If portability is a problem then twin Honda 2000's are even better.

Get a regular 2000 and a Companion 2000 which gives you a 30 amp outlet.

'16 FORD F250 6.7 373 FX4 Lifted with 35" Toyos Air Bags

'16 Arctic Fox 25R. Xantrex 2000 inverter/charger, four Trojan 6 volts, 450 watts solar.

Posted By: christopherglenn on 08/10/11 10:02am

A 2k *should* run the AC at sea level, or within a few hundred feet of it. If you are going up a few thousand you will want 2500-3000+ watts. The inverter generators are MUCH quieter but cost more, the contractor generators are louder MUCH louder and cheaper and louder. (did I mention they are louder)? Most people trying to run on a single 2k end up putting the fridge on gas, and shutting the converter off (at the braker) to get the AC started. There isn't alot to spare on a 2k.

2007 Chevrolet 3500 CC/LB Duramax/Dually 4X4 Mine r4tech, Reese Signature Series 18k +slider, duratrac, Titan 62 gallon, diamond eye, Cheetah 64
2011 Keystone Fusion 405 TrailAir & Triglide, Centerpoint, gen-turi, 3 PVX-840T, XANTREX FREEDOM SW3012, G614

Posted By: Center Pin on 08/10/11 10:56am

My Yamaha 2400is will start and run my 13.5 at 9000 ft, but don't try to run anything else. After hearing a Honda 3k, that will be my next genny if the 2400 ever wears out.

Trailer: 07 Tango 299BHS w/ 225/70R15 LT Load Range D

TV: 2004.5 Dodge 610 CTD 3500 QC 48RE 2wd Laramie SRW, FP Gauge, FASS 95/95, Rhino Lining, Hensley Arrow, Air Bags & Compressor, Canopy, Custom Boat Rack.
Been running B100 home brew June 2008!

Posted By: redwake on 08/10/11 11:21am

champion 3500 hasn't let me down... has 30 amp plug... the new models have remote start as well (mine doesnt)

TT: 08 Monterey 27 PT by Extreme RV
TV: 05 Eddie Bauer Expedition w/5.4L 3.31 Gears ">
Hitched with a Husky WD & SC.
Powered by Champion 3500

Posted By: MeandMyLabs on 08/10/11 11:47am

I had an issue with my Yamaha 2400 this year. It ran the AC just fine until the compressor cycled off (several hours on a very hot day) but when the thermostat called for it to cool again, the generator did not have enough output to start it. I tried starting the fan first and then kicking in the compressor to no avail. I had everything else off in the TT (except the converter). After this experience, I now have a Champion 3500-4000 watt for using while running the AC.

Because of the previously mentioned incident, I would not recommend the 2400 if your intentions are to run the AC.

2017 Salem Hemisphere
2009 Chevrolet 2500 HD 6.0 L

Posted By: Crazyfoe on 08/10/11 01:53pm

Anything smaller than a 3k is wasting your time and or going to fail to turn over your compressor. I've got a Honda 2k and it won't do squat for ac no matter where I am. Either get two 2k's and link them or get a 3k for one single unit but heavier.

04' Chevy Silverado 2500HD 496 cu in - Allison
'06 Keystone Cougar 304BH
1 Honda eu2000i generator
Drawtight Activator
Huskey Weight Distribution System
1 Spazzed Weimaraner

Posted By: 2manytoyz on 08/10/11 02:47pm

For a 13,500 BTU A/C unit, the minimum size should be the Yamaha EF2400iS (or the new HC version). I've had no problems running my A/C for the past 5 years with mine.

Video of mine running the A/C at a rest stop:

After talking with a few people, this generator is too small to run a 15K A/C unit. So are many 3KW generators. A 3.5KW-4KW looks to be the right size, but "I" haven't tested it myself, take it with a grain of salt.

The big plus about staying with a 13,500 BTU A/C unit is the much lower startup current. Consequently, it can be run with a 70 lb 2.4KW Yamaha. A slightly larger 15K A/C unit requires at least a 3KW generator, which are ~140 lbs (Honda or Yamaha).

Here's the testing I've done with mine:

Merritt Island, FL
2007 Rockwood TT 2502
Equalizer Hitch
2010 Ford F-150 FX4 -w- Max Tow Package
Yamaha EF2400iS

Posted By: taken on 08/10/11 03:20pm

I also ran a Yamaha 2400 on my previous trailer with a 13.5k ac. Worked great at any elevation. However, when we upgraded our TT this year to a more modern unit with a larger converter running the ac was hit or miss, more miss. We sold it and now have the twin Honda's. Best of both worlds. When you don't need it for ac you can just bring one. When you need it, you have the second.

Regards, Rodney
TV - 2017 F350 SRW CC SB 4X4 6.7
TH - 2015 FR XLR 395AMP

Posted By: redwake on 08/11/11 10:49am

taken wrote:

One other thing to consider. The Yami 2400 and the Honda twin 2000's fit under your tonneau cover. Most others won't.

the champion fits in fact i use to pop my cover open but leave it in the truck bed before i got the suv

Posted By: facory on 08/10/11 04:37pm

redwake x 2. Our 3500 with a 30 amp outlet runs a 13.5k or 15k with ease. If you want to run the electric water and/or the microwave at the same time then consider at least twin 2000's.

2008 Cruiser RV Fun FinderXtra
Ford F150 Lariat 4x4 SuperCrew 5.4L 6.5' Bed 150" WB 3.73
Schwinn Mountain Bike

Posted By: BlindGuynAR on 08/10/11 06:38pm

I like the yamaha 3000iseb. It is heavy though.

Runs my 15k without issue in econ mode. It can boost an extra 500 watts for up to 20? something seconds. So it can handle 3500 watts for a short time.

Think about adding a hard start kit to your a/c compressor. Your a/c and your geny will thank you for it!

2013 Montana 346LBQ Mountainer edition
2017 GMC Denali 3500HD 4x4 DRW
- B&W Turnover w/Andersen Ultimate 5er hitch
- Transfer Flow 40ga aux tank/tool box
- Gatorback Mud Flaps
- Ultimate Camera Package

Posted By: taken on 08/10/11 06:50pm

One other thing to consider. The Yami 2400 and the Honda twin 2000's fit under your tonneau cover. Most others won't.

Posted By: GeoBoy on 08/10/11 08:24pm

Go with twin Honda's or twin Yamaha 2000's, easy to handle.

Posted By: BlindGuynAR on 08/11/11 12:42pm

3000iseb fit under my cover as well.

Whatever you get invest in something quiet. Camped nexted to some folks a few weeks back & good gosh we spend the nice weather night in the TT cause we couldn't hear ourselves think it was so loud!

Felf like cutting their fuel line or stealing their spark plug at one point[emoticon]. I was happy when that beast ran out of gas at 2:30am and they didn't refuel. They probably dumped 15 gals in it throughout the day. Maybe they ran out $$$.

Posted By: USMarine0369 on 08/11/11 03:28pm

I picked up a Champion 3500/4000 at Cabela's with Remote start. Haven't used it yet but I am looking forward to it. I was borrowing my brother's Honda 2000 but not big enough to run A/C.
I am looking to mount it on rear bumper and run exhaust to the roof level to cut down on sound a bit.

Posted By: camper.david on 08/11/11 05:17pm

We have used a Honda EU 3000 for years and find them to be pretty much bulletproof. That said, I hear good things about the Yamahas also. If you can, I would borrow a 3000 to try your 15000 BTU and see if it works. If not, then you know you need to get two 2000s. The inverters are the way to go, as they use much less fuel and run quieter. Just don't look at the price, and you will be fine [emoticon]. Bear in mind also that campers can be different as well. We had a Jayco 27BH that the Honda struggled to start the AC, but it has never failed on the larger 31BHS.

Posted By: facory on 08/11/11 09:23pm

To BlindGuynAR: Most every reputable CG has rules that prevent anyone from running their generators beyond 8:00 PM. I would report the camper who ran his until 2:30 AM and insist that the rule be enforced. If they continue they will be asked to leave. Problem solved.

Posted By: mikeb9550 on 08/12/11 05:01am

For me it was only down to two choices.

1. Buy a Champion 3500 and live with the noise

2. Buy 2 Honda 2000s

I went with the Champion due to a power outage at home. I just couldnt see spending 2K on the twins for once in a blue moon usage. If we dry camped a lot I would have done it. I have never stayed at a CG that hasnt had 30 amp. If we start doing it regularly, I will buy the 2 hondas. I dont see that happening.


2014 Dodge Ram 1500 Hemi 3.92, Hensley Arrow Hitch

2006 Jayco Jay Flight 26BHS

Posted By: HighCover on 08/12/11 07:57am

I have used the 2400 Yamaha since 2007, including dry camping in hot whether. It can run a 13.5 AC unit all day and all night, not problems. The only thing we can run with the AC is the microwave, but, when we need to nuke something, I just cut the AC of for the few minutes needed to cook.

Couldn't be happier with it.

2010 F-150, 5.4L, 3.73
2011 Edge M17

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