Calculating electic usage

[tasdisr]

I could not find a post on this.
Is there a way to calculate the electrical usage of a pump? I am trying
to figure out a rough idea of how much it will cost to run the pump
on a pooll

[larry2338]

Do a search for and check out this thread:

Saving electricity - replacing an old pump/motor

[mas985]

From most accurate to least accurate there are several methods:

1) Use a watt meter to measure the power. Not too many people have access to this.

2) Measure the current and voltage on line, multiply them together and take 90% of that number for a power factor. Again, requires an AC Volt/Amp meter.

3) Use the maximum amp rating on the pump and multiply it by the voltage rating and again multiply by 90%. This gives you watts but tends to over estimate.

4) Use braking HP (HP * service factor) for kwh. Could have up to 25% error.

Multiply watts by the run time in hours over the month, divide by 1000 and you get kwh for the month. This is what the power company uses for billing. Your rate should be on your last bill.

[Poconos]

Another way is to use the watt-hour meter, the house electric meter. If you get ambitious and get to the right person at the electric company someone can tell you the meters calibration. Used to know what the numbers meant but that was many years ago. The info you are looking for is the Watts per revolution of the disc. Pick a time when the disc is hardly moving compared to when the pump is on, which is at a low house power time. Fire the pump and count revolutions in some time period like 10 minutes or so. Assuming 10 minutes for the sake of the calculation, figure the watts consumed in the 10 minute period by multiplying revs by the cal factor to get watts, then multiply by 6 (60 / 10) to get the number of watts in one hour. Then divide by 1000 to get KiloWatt-Hours. On your electric bill there should be a cost breakdown for $$ per KWH (KiloWatt-Hour). Knowing the number of KiloWatts per hour multiply by the cost per KWH and you will have the cost of running the pump for 1 hour. The electric meter gives you the true power consumed. Just make sure while you're counting revs that nothing in the house like a refrigerator or air conditioner kick in to mess up the reading. (ajs-1)
Hope this helps.
Al

[cgc2]

I could not find a post on this.
Is there a way to calculate the electrical usage of a pump? I am trying
to figure out a rough idea of how much it will cost to run the pump
on a pooll

Here is a link:
https://www.sce.com/forms/ApplianceEnergyEstimator.aspx

There is more to timing a meter than is posted above. And the Kh number on the meter is the multiplier or referenced "calc factor" for the gearing on a residential meter.
Usually, its around 7.2, but your region/utility may vary.

I will post the full meter timing method in a bit.
Also, turn off all breakers except for the one serving the pump when performing this function, as you do not want to include any other load from other household appliances.

[mas985]

Not sure why I forgot about the utility meter method since that is actually what I used. Oh well.