conversion from KWH to KW?

[Coastalguy1]

I recieved a power company useage sheet for an existing residence that showed the largest useage for a month at 1145KWH. My question, how do you convert KWH to KW? I am adding a 4 car garage to the service; I know that by NEC I can take the existing peak KW x 1.25 and add new load to derive at my new load summary. Thanks in advance for the help.

 

[rbalex]

I recieved a power company useage sheet for an existing residence that showed the largest useage for a month at 1145KWH. My question, how do you convert KWH to KW? I am adding a 4 car garage to the service; I know that by NEC I can take the existing peak KW x 1.25 and add new load to derive at my new load summary. Thanks in advance for the help.

You can't determine maximum demand from what you have supplied so far. Dividing the kW-hr by the total number of hours in the billing period will only give you an average kW. In order to apply 220.87 you will need to actually measure the maximum demand. Most folks use the exception; a few jurisdictions will even allow shorter periods if it can be established that it will indeed indicate the annual maximum demand.

 

[Besoeker]

My question, how do you convert KWH to KW?

The short answer is that you can't.
The first, kWh, is energy. The second, kW, is power.
It's a bit like asking how to convert miles to mph.

 

[Hv&Lv]

Look at the meter. If it one of the new smart meters, it may have a kW reading on it. It will flash "PD" (or something like that) beside the reading.(peak demand). Some meters have this feature, some don't. Depends on the POCO.

 

[K8MHZ]

I recieved a power company useage sheet for an existing residence that showed the largest useage for a month at 1145KWH. My question, how do you convert KWH to KW? I am adding a 4 car garage to the service; I know that by NEC I can take the existing peak KW x 1.25 and add new load to derive at my new load summary. Thanks in advance for the help.

From the info you supplied, all we can see is that the average load during that month was less than 7 amps. So, that info is really of no use and does not indicate a peak value.

What you have to watch for is heating loads. They can suck up a lot of juice.

Example, electric water heater, 16.6 amps.

Plug in space heater, 12.5 amps.

Each burner on an electric range, 16.6 amps.

6000 watt electric oven, 25 amps.

Electric clothes dryer, 20-25 amps.

If the house doesn't have any of these (all gas), that is a big difference from a house that does. If all the above were turned on at once, that is just a tad over 140 amps.

 

[Jraef]

As the others have said, you can't do it with that information alone. Think of it this way:

1145kWH = 1145kW for one hour, or 1kW for 1145 hours, or 1.567kW for 730 hours (since there are only approx. 730 hours in an average month). So what has that told you about peak loading?

Nothing.