Electrical costs for my pool

[Rangeball]

KWH is approximately (Amps X Volts divided by 1000) X Hours. At max current, your motor would use 12AX120V=1440W Dividing by 1000 gives 1.44KW X 24Hours= 34.56KWH per day, so at $0.083 per KWH, you are using $2.86 worth of electricity a day, or roughly $86 per month. Double that if that is a 220 motor.

The plate current is max, and you probably aren't using that. The only way to know how much current you are using is to measure it.

Thanks.

I was always under the impression that I was spending around $35 per month. This makes 12 hour run time look much more attractive.

[mas985]

If you decide to use your house electric meter, here is a formula you can use:

kwh = 3.6 * Kh * R / T

Kh is the meter constant and usually printed on the meter. Most are 7.2.
R is the number revolutions you are timing. I use 10 when the pump is on and 1 when it is off.
T is the time in seconds for R revolutions.

If you measure with the pump off and then on and subtract the two, you get a pretty accurate number for just the pump.

[JohnInSoCal]

my electric meter gives the reading for KWhrs but I have so much stuff going on generally it wouldn't be very practical to try and shut everything down and monitor the pool pump or AC. Currently we are using about 100 KWhrs a day, my last electric bill was $811 a personal record

[Rangeball]

Based on the estimated cost arrived at above, my pump accounts for 34% of my electric bill.

Timer here we come

[rpoldervaart]

Wow. Glad I posted a popular topic. I wasn't aware of the Power Factor. And it sounds like I need to do some more research on calculating motor costs.

I've found several articles on the web to read, but alas, my work is calling me... In addition to the PF number, there also seems to be a .00173 number that is also being thrown in. This was used to calculate kVA. Siting from http://www.cop.com/SEUhtmDOCS/SEU17.htm, the formulas are:
kVA = 0.00173 * V * amps
kw = kVA * PF * .01 (PF being % between 1-100)
running for one hour would be kwh and then multiply by number of hours times cost per kwh.

Now, looking at the calculations above and the linked site, they are using the stated amps on the nameplate, where I am using the measured amps on my amp meter. It looks like the only place they're using the measured amps is to help calculate the PF.

So what is the 0.00173 number? If I throw in the .00173 number and a 90% power factor, I'm actually increasing my kwh because the .00173 increases more than the .9 decreases it.

Robert

[mas985]

Wow. Glad I posted a popular topic. I wasn't aware of the Power Factor. And it sounds like I need to do some more research on calculating motor costs.

I've found several articles on the web to read, but alas, my work is calling me... In addition to the PF number, there also seems to be a .00173 number that is also being thrown in. This was used to calculate kVA. Siting from http://www.cop.com/SEUhtmDOCS/SEU17.htm, the formulas are:
kVA = 0.00173 * V * amps

This is for a 3 phase motor. Standard motors are kVA = 0.001 * V * amps

kw = kVA * PF * .01 (PF being % between 1-100)
running for one hour would be kwh and then multiply by number of hours times cost per kwh.

Now, looking at the calculations above and the linked site, they are using the stated amps on the nameplate, where I am using the measured amps on my amp meter. It looks like the only place they're using the measured amps is to help calculate the PF.

So what is the 0.00173 number? If I throw in the .00173 number and a 90% power factor, I'm actually increasing my kwh because the .00173 increases more than the .9 decreases it.

Robert

See comment above.

Also, to make it simple, kwh = Volts * Amps / 1000 * (PF%/100)

[cleancloths]

As others have said, the best way is to use the house electric meter. You don't have to turn everything else off, just make sure it stays constant when you run the test. You might want to unplug your refridgerator, as you cannot control when it will cycle. The power factor can vary alot. I have an old fridge that has a power factor of about 0.6 rather than the 0.9 mentioned.

Volts times amps only works for DC not for AC.

[mas985]

my electric meter gives the reading for KWhrs but I have so much stuff going on generally it wouldn't be very practical to try and shut everything down and monitor the pool pump or AC. Currently we are using about 100 KWhrs a day, my last electric bill was $811 a personal record

Thats why you measure it with the pump on and then off and take the difference. That way it does not matter how much stuff you have on.

[rpoldervaart]

OK. So I've added Power Factor to my spreadsheet as a changeable parameter. This is probably pretty close, and I'll try to get out and count the meter spins to verify soon.

http://home.houston.rr.com/poldervaa...the%20pool.xls

Thanks,
Robert

[Big_D]

The Intelliflo provides actual flow and watts consumed data to produce that flow . So if you have a restrictive system the flow per watt is lower. If I could figure out a way to have enough back pressure to run the Trio Pure and cleaner and keep the flow low I could clean my pool on 440 watts hr x 14 hrs a day. or 6.1 total amps a day.

The cool aspect is the pump will calculate the optimal flow per # of turn over per day for you if you do not use preset flow rates.