Air Conditioner on a Generator

[Parker Buckley]

Last year, I converted a window air conditioner to use external to our Scamp, with the air piped in and out, looking a bit like the lunar lander. This year, we're probably going to spring for a Honda generator. I know that conventional wisdom is to buy the 2000 watt unit. Thinking my home window unit may have lower power requirements than the typical roof-top unit, I measured the current with a Kill A Watt meter. The max current I see is 8 amps at the moment the compressor comes on. If I play stupid and short cycle it by turning the temp up and immediately back down, it draws a huge amount of current and delays the compressor start. But if I let the unit cycle itself, it only draws 8 amps when starting and then drops back to 4 or less. Is there any tolerance with the Honda for a momentary spike, just in case I'm missing the actual peak current with my measurements? If I add a starting capacitor (what if there is already one there?) as has been described in a recent post (can't find it) would that help get me to a low enough starting load to get by with the 1000 watt generator? We don't have any other loads other than battery charging for our led lights (no microwave, etc). I would really like the lower cost/weight//size/fuel consumption of the 1000 watt unit, but I don't want to get stuck with something that won't do the job and then have to upgrade. Comments welcome!

Thanks,
Parker

[Darwin Maring]

Parker,
The calculations show 960 Watts.
Volts 120 X 8 Amps = 960W. You would be pushing it to the limit.

Here’s a suggestion: Take the camper to a dealer that sells the Honda generators and let them demonstrate it on your camper.

If it does work and you purchase the 1K then you must only run the AC and nothing else and use 12gage wire as the smallest wire and as short as is practical. The lower the wire gage, the larger the wire. 10 is larger than 12 and 14 is smaller than 12.

It is important to have the Generator far enough away from the camper to insure you do not get carbon monoxide inside.

Personally, I would spend the extra $$ and get the 2000W model.

[Parker Buckley]

Parker,
The calculations show 960 Watts.
Volts 120 X 8 Amps = 960W. You would be pushing it to the limit.

Here's a suggestion: Take the camper to a dealer that sells the Honda generators and let them demonstrate it on your camper.

If it does work and you purchase the 1K then you must only run the AC and nothing else and use 12gage wire as the smallest wire and as short as is practical. The lower the wire gage, the larger the wire. 10 is larger than 12 and 14 is smaller than 12.

It is important to have the Generator far enough away from the camper to insure you do not get carbon monoxide inside.

Personally, I would spend the extra $$ and get the 2000W model.

Yep, I did the math too and realize how close I am to the limit. Since this is a momentary load, I was hoping the Honda might withstand a brief period near the max rating and/or I could add the capacitor to the ac unit to soften the start.

Good idea on taking the ac unit to the generator dealer! I was going to order from Wise, but maybe I can find someone nearby.

Thanks,
Parker

[John H]

Make your test on a 100 degree day and maybe at 4000 ft altitude or higher and report back. I have found that it is not always starting load that is a problem. My AC will draw as much 300 watts more as the head pressure increases due to the high heat.
Make sure to let the compressor run for 15 minutes to insure max head pressure.

The little Honda is a great generator, but is only capable of less than 1000 watts (continuous) at its best at sea level and it will run it for a while and slowly lose the battle. Remember that 8 amps X 120 volts is 960 watts is what was measured, but what is the name plate current. I don't think the 1K Honda will handle it even under ideal conditions.

[GeorgeR]

Honda specification for EU1000I is 1000W max. and 900W is in its running mode (7.5A). I believe that using EU1000I would not be sufficient in your application. Just a simple measurement of AC current is not sufficient to make a judgment if EU1000I would be adequate. Power needed to start and run a compressor is related to power factor and a load to source impedance match. You could play with tuning capacitor on the compressor to improve power factor by but this could have been well engineered already. Everything else is fixed and, as recommended earlier, the actual test in full spectrum of conditions would be the best, ultimate test. Go with 2KW. Camping World has Honda 2000 for $999.

George.

[John Hussey]

Not Camping World for the Honda generator!

Buy from Wise sales instead and save yourself $130.00. I just bought my Honda eu2000i for $869.00 delivered to my door! Call on the phone to order. If Ed doesn't answer, ask for him. Mention this site to get their already discounted price lowered to the above.

[Parker Buckley]

Well, thanks all for your feedback. I suspected as much but thought there might be a glimmer of hope that the 1000 watt generator would do the job. I'll be ordering the 2000 watt machine from Wise. There is probably also a plus to buying the larger unit in terms of re-sale value, since that's what everyone else uses. This will start a whole new learning curve in terms of how to carry the generator (13' Scamp and Subaru Outback), setting it up, etc. Maybe a tongue box at some point, but there's not much room there. I'll try to get a plastic box for it to contain whatever gasoline smells there may be and probably carry it in the Scamp. Maybe a propane conversion at some point....anyway, here we go again.

Happy Trails!

Parker

[Ken C]

THere are number of users at the yahoo honda generator groups using a EU1000 running the smallest window A/c unit you see in wal-mart.

[The Hobo]

Not Camping World for the Honda generator!

Buy from Wise sales instead and save yourself $130.00. I just bought my Honda eu2000i for $869.00 delivered to my door! Call on the phone to order. If Ed doesn't answer, ask for him. Mention this site to get their already discounted price lowered to the above.

Can you post a phone # and/or link?
Thanks.

[Joe Z]

Wise Sales

http://www.wisesales.com/HondaGenNEW.html

[Parker Buckley]

THere are number of users at the yahoo honda generator groups using a EU1000 running the smallest window A/c unit you see in wal-mart.

Yahoo Honda generator group??? Good grief! I guess I should have expected that. I remember commenting many years ago that there seems to be a magazine for every activity. In 2009, why not a user group?! I'll take a look, as we're probably talking the same size AC unit. If the AC starts softly, of its own accord, it doesn't draw much current. If I force it, such as switching on the power from an external source while the AC switch is already on, it draws a bunch of current. Thanks....I'm about to call Wise to order the 2000, but I'll try to find the Honda generator group first.

Parker

[The Hobo]

Wise Sales

http://www.wisesales.com/HondaGenNEW.html

Thanks for the link.
I called them for info,
but unfortunately,they won,t ship to Canada... Eh

[Parker Buckley]

Okay, the deed is done. I ordered the 2000 from Wise (talk to Ed!) for $869 along with their non-venting gas container. For mentioning Fiberglass RV, he threw in the DC charging cables. Cool! I just bought a $900 jumper system!

I did check the Yahoo group regarding experiences with the 1000. It sounds like the 1000 could possibly work if I'm willing to experience occasional breaker trips, etc., but I don't want to risk the frustration of all that.

Parker

[Pete Dumbleton]

Thanks for the link.
I called them for info,
but unfortunately,they won,t ship to Canada... Eh

Likely the reason they won't ship to CA is because the CA-spec and US-spec Hondas have different grounding wiring; the US-spec wiring will not meet CA requirements.

The result is that one cannot connect two CA-Hondas together for one output.