Anyone with experience with generators and compressors?

[JoggingGuy]

I rode out the storm here in North Houston with no problems other than being without power for 14 hours. But my neighborhood had no power for over 2 weeks when Alecia came through in 1983, so I know how bad it can get.

I have looked at generators to run the house systems for a while, but it never included the central air because of the problem with starting the AC compressor. But AC was the real necessity this time because it was so hot and humid and I have a wife with asthma.

I don't want a stationary unit, but I did find this one: Guardian Ultra Source 15,000 Watt Electric Start Generator

I have a 4 ton Trane unit that draws 19.50 amps at 240 volts (4680 watts) when running according to my clip-on ampmeter. Question is, would a generator like this be able to start the compressor? It looks like it would have no problem running the thing once it was going.

Anyone have any experience with generators starting motor loads like this? Thanks

 

[Al]

Basically you need about 3 x the watts of the A.C load (Reactive Load)

http://www.hondapowerequipment.com/gencho.asp

I'm not an expert. But if you want to run this kind of load you should go with Natural Gas or Fuel oil. Gasoline is a pain and this thing will drink huge amounts of Gasoline. I have a 6K generator and usually run about 500 to 1500 watts with it. Even that minimal load sucks about a gallon in 5 hours.

 

[andyd]

I would think so. 15kw @ 240v is over 60amps off the top of my head. I imagine the AC unit has a dedicated breaker in the panel. Whats the breaker rated for?

 

[416Rigby]

I have a 15KW diesel gen that runs my house, including a 3.5 ton Trane AC unit with no problem. Make sure you have a good transfer switch for it.

 

[JHZR2]

Consider installing a Mitsubshi "mr slim" single room A/C unit, and then wiring that in. This way you can condition just one room, so youll save $$ on fuel, your wife can have a space that is good fir her, and you can have a much smaller genset.

My GF's parents have this setup in the USVI... With a 5kWe (I think) diesel genset.

JMH

 

[Al]

quote:

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Originally posted by JHZR2:
Consider installing a Mitsubshi "mr slim" single room A/C unit, and then wiring that in. This way you can condition just one room, so youll save $$ on fuel, your wife can have a space that is good fir her, and you can have a much smaller genset.

My GF's parents have this setup in the USVI... With a 5kWe (I think) diesel genset.

JMH

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Excellent point. Even a 7000 BtU unit of say 10 EER draws only about 700 watts. Running all the time it will keep a room cool. There's your answer.

 

[Willy_G]

Whatever you do, install an interconnect switch! Sometimes called a throw-over, or line disconnect. This disconnects you from your utility service to keep from backfeeding a line, so you don't end-up re-energizing your service xfmer and/or high-voltage line. You could easily step-up your 240v to 13kv! Even if all the lines are down, you don't want any ground faults, or shock/kill any linemen restoring service.

Although hard to get ahold of, expensive, and dangerous, you could always get a large capaciter(s) to help out starting the motors. I would not reccommend this unless the caps. could be professionally installed per all applicable regulations.

 

[labman]

Originally posted by Willy_G:
[QB] Whatever you do, install an interconnect switch! Sometimes called a throw-over, or line disconnect. This disconnects you from your utility service to keep from backfeeding a line, so you don't end-up re-energizing your service xfmer and/or high-voltage line. You could easily step-up your 240v to 13kv! Even if all the lines are down, you don't want any ground faults, or shock/kill any linemen restoring service.snip....


Why are those things so big and expensive? Saw one at Home Depot yesterday. It was about 2' high and almost $300. Why should it need to be so much bigger deal than the 100 amp main breaker in my box?

I happened on a deal on a generator. I am in bad shape if I lose power. I can run a few extension cords for lights and the refrigerator, but connecting up the furnace and pump would be a major hassle.

 

[416Rigby]

The transfer switches are mostly empty space inside the box. I watched the electrician that installed mine as he hooked up all the wires. He said the space was to allow for bundles of large-gauge wires inside the box. He was right, as the wire from the meter box to the switch was 0/4 gauge. Quite large stuff, rated at 500amps. The controller itself is a small module, about the size of a calculator. As for the price, I think the companies that make them are used to gouging their customers.