Generator

[MonteC]

Anybody know how to convert how many kWh's used a month into how big of a generator you would need?

I looking to buy a standby generator for the house. The power has gone out twice this month. I was in the fucking shower today with a head full of shampoo. :mad:

The very most we use would be almost 1400kWh (1392kWh) over 31 days back in January. Lowest would be 430kWh over 28 days in April.

What size generator would I need to run this house? I would prefer a diesel.

[Harry]

You would not go by the monthly use. You should have a 200 amp service to your house. If you are loking for something to run your whole house, you would want to buy something like a 20kw generator.

[LXtasy]

I think you could get away with a 22kw generator. Think about it. Your average is only 45kw a day. Divide that by 24 hours and you have 2 kw. NOW that is your average. You need to think the major draw would be dryer, hvac system, and refrigerator. If all items started up at the EXACT same time would be the biggest draw of it.

I am a big fan of generac generators. You can get larger generator if you want/can afford. But this is the one I have been eyeing and want to add to my house.
http://www.generac.com/Residential/Quietsource/Products/22_kW/

[MonteC]

Arent the generacs on LP?

[Chillerman]

First things first. Your total kwh usage has absolutely nothing to do with the size of generator your going to need. It doesn't matter what your service size either in determining your kwh usage. Your kwh is totally based on how you live in your house.

Harry is right that you probably have a 200 amp service. What you need to do is determine how much of your house needs to operate while on emergency power. If you want the whole house, then you need to determine the total load in amp draw that you will induce on the generator.

All loads that are resistive (like stove's, water heaters) do not require any inrush amps like an inductive load does (hence, air cond., refrigerators, and anything with a motor). You will notice that all generators have running amps and surge amps. This surge factor is related to the inrush or start up current of an electric motor like your a/c system. This is where it gets a little confusing as inrush can be as much as 7 times the rated load amps. This is what you have to size for.

You may have a little 2 ton heat pump that might be able to start up on a 12-15 kw generator. But if you have multiple systems in your house or say a larger 4-5 ton system, then it might take a 25 or larger kw generator just to handle start up. Just look at the data tag on your ac system, it will tell you about the required amps to keep it going. Just do the math from there and let your check book be your guide.

[MonteC]

Ill look at it, but its a newer model (house was built late 08, early 09). The house is only 1700sqft so it cant be too big of a unit.

[MonteC]

I cant make heads or tails of that stupid tag.

[LXtasy]

Whats the model number? You probably have around a 2.5 or a 3ton system

[MonteC]

So as long as I get something that can handle turning on the a/c unit I should be set?

http://i8.photobucket.com/albums/a11/spectraredz/IMG00712-20110828-1745.jpg

[LXtasy]

You have a 3.5 ton unit sir.

[Chillerman]

So as long as I get something that can handle turning on the a/c unit I should be set?

http://i8.photobucket.com/albums/a11/spectraredz/IMG00712-20110828-1745.jpg

Yes you should be alright with that. I did not see the rest of your data tag that shows the RLA of the compressor. Also look for the LRA of the compressor if it shows it on the tag. That will give you an idea of starting amps. If the tag does not show the LRA, then take the RLA and multiply times 7, this will give you and approx starting amps.

Now to convert amps to watts just take your voltage which will be like 240-250 and multiply the amps which will give you watts.

V x A = Watts

[REDRAGTOPRS]

Rob, your model number is "RQNL-042JK. The "042 tells you that you have a 3.5 ton unit, as the number goes in increments of 12's....A 2 ton unit would be "024" for example...If the number is more than "036", but less than "048", then it's a 3.5 ton system....Just an FYI.....

[Darryl Buckner]

Yup. And you can get Genracs in anything from LP, to gas, to diesel. My house is about the same size as yours and I run it fine with a 10kw, but I don't use the AC, stove, or dryer. It operates the frig, fans, TV, and everything else fine. The cheapest place to buy a generator for business, home, or RV, is a place online called Norwall power systems. I think they are in Arizona, I have purchased several from them, and they carry wiring kits if applicable, and usually free shipping, even on larger units..