I just bought a dimensions pure sine 800w inverter. My intent was to run a 5000btu air conditioner while I was driving. I tried it with an older ac and it overloaded it on startup. I could not find the specs on the ac . My question do you think if I buy a new ac that it will handle the startup. I know that it takes 2/3 times the watts to start it. The new acs say low startup but I cant find the exact watts for the start up.
Dimesions pure sine inverter question
- Thread starter dvorocks
- Start date
dwh
Tail-End Charlie
Even the most efficient small window unit that I found some years ago when I was looking (and I looked at the specs on them all), was a 5,200 BTU unit by Frigidaire, which had a some sort of "easy start" technology and drew 600w running and 1300w starting.
So no, you're not going to run a 5000 btu window unit from an 800w inverter.
So no, you're not going to run a 5000 btu window unit from an 800w inverter.
dwh
Tail-End Charlie
Because startup is momentary and most people will plug it into a grid so who cares about startup?
If the inverter can actually handle 1500, you *might* find a window unit that it can run. I wouldn't hold my breath though.
But even if you had an a/c with a 1300w startup and your inverter could handle 1500w surge - you still might have a shutdown as the voltage on the DC side drops from the load. If it drops below the inverter's cutoff point, then it'll shutdown from that. 1500w / 14v is still over 100 amps so you'd need pretty thick wire to feed that inverter if you wanted to prevent shutdown from momentary surge.
If the inverter can actually handle 1500, you *might* find a window unit that it can run. I wouldn't hold my breath though.
But even if you had an a/c with a 1300w startup and your inverter could handle 1500w surge - you still might have a shutdown as the voltage on the DC side drops from the load. If it drops below the inverter's cutoff point, then it'll shutdown from that. 1500w / 14v is still over 100 amps so you'd need pretty thick wire to feed that inverter if you wanted to prevent shutdown from momentary surge.
4x4junkie
Explorer
I have a 6000 BTU Frigidaire that I bought around '07 that is rated 4.9 amps @ 115V (so about 563 watts). Scaling that down should equate to a touch under 470 watts for a 5000 BTU unit (which I guesstimate would have a startup draw under 1000 watts). I also would think A/C units have gotten more efficient over the last 8 years too.
Things to look for in a household-type A/C unit that are easy to spot are the Energy Star logo, and the "EER" number (higher is better). Mine has a 10.7 EER, but I know many are up to the mid-11's now, maybe even 12 or higher. The higher the EER, the more efficient it is.
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dwh
Tail-End Charlie
Can't find the email from Frigidaire. Here's a copy of it that I posted to NAWS forum way back when:
http://forum.solar-electric.com/for...smallest-most-efficient-a-c?p=76105#post76105
That was their most efficient unit in '09, and it drew 1,322w starting. So I misremembered the running watts as 600, when it was actually 475. Close enough.
I highly doubt that there is a 5k BTU unit on the market that has a startup of 1000w or less - unless it's one of the Danfoss units.
http://forum.solar-electric.com/for...smallest-most-efficient-a-c?p=76105#post76105
That was their most efficient unit in '09, and it drew 1,322w starting. So I misremembered the running watts as 600, when it was actually 475. Close enough.
I highly doubt that there is a 5k BTU unit on the market that has a startup of 1000w or less - unless it's one of the Danfoss units.
IdaSHO
IDACAMPER
Why would you think that?
The technology hasnt changed a bit, even in the last decade.
dwh
Tail-End Charlie
Frigidaire hasn't made that model for years, but there's still a listing archived on Amazon:
http://www.amazon.com/Frigidaire-FA...p/B0009T6ACO/ref=cm_cr_pr_product_top?ie=UTF8
http://www.amazon.com/Frigidaire-FA...p/B0009T6ACO/ref=cm_cr_pr_product_top?ie=UTF8
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DiploStrat
Expedition Leader
FWIW - I have a 6k BTU Sharp A/C. The minimum inverter that will start it is a 2800w Magnum.
The problem is the starting surge of the compressor, which is generally about 5x the running load. My unit draws about 50A when running, which would come out to about 250A or, grossly 2500w. If you use a generator, then the prime mover simply sags a bit and the A/C starts. With batteries through an inverter you need a massive inverter. (And you are still going to drain that battery bank fast.)
The problem is the starting surge of the compressor, which is generally about 5x the running load. My unit draws about 50A when running, which would come out to about 250A or, grossly 2500w. If you use a generator, then the prime mover simply sags a bit and the A/C starts. With batteries through an inverter you need a massive inverter. (And you are still going to drain that battery bank fast.)
LeishaShannon
Adventurer
See if you can find an inverter (variable speed compressor) window AC unit? Our inverter split system draws 350W flat out and less than 200W on low. Runs fine on a Victron 350VA inverter if I run it in "silent" mode which limits the draw to ~ 250W
DiploStrat
Expedition Leader
Never heard of a variable speed compressor. Don't know about availability in the U.S., but this looks very interesting. http://www.appliancedesign.com/arti...ompressors-change-the-game-for-hvacr-industry
4x4junkie
Explorer
Somehow they have been pushing those EER numbers higher... I seem to remember reading something about a switch away from R-22 freon to R-410 or something around that number also.
Edit:
It's R-410A
http://en.wikipedia.org/wiki/R-410A
Wikipedia said:
That's quite a big change if you ask me...
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