Electrical costs for my pool

[rpoldervaart]

I finally went out and measured the amps on my control panel while turning the equipment on and off. Bottom line, the scheduled runtime of my filter, cleaner, chlorinator, and control panel itself at Houston's power rates is costing me $120/month. And I'm only running the pump for 8 hours. Add in the additional pump and waterfall pump time when people are swimming, and I'm up to about $160/month. Now I understand more why my bill went from $300 to $500 this summer. My builder said the electrical use would be about $30/month. Boy was he ever wrong... Attached is the spreadsheet with the numbers.

My pool is 20,000 gallons. My pump is overkill, so I'm wondering about the return on investment of going to a smaller pump. I'm also in the process of switching from Reliant to Dynowatt and my power costs should go from .168 to .135, or $166/month to $133/month.

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

Robert

[JohnInSoCal]

how did you measure the amps ? I think my pump costs around $200 a month in the summer to run but I don't know for sure. We pay 31 cents a KWhr.

thanks,
-- john

[rpoldervaart]

I bought a clamp on type of amp meter. You can measure volts in parallel by just putting the two probes of a meter on the contacts. But for amps and an older amp meter, you have to measure amps in series. In other words, take one wire off and put your meter in series with the ciruit. Along came the clamp on meters and you just put the clamp around the wire (either leg of 220 or the hot or neutral of 110) and it will tell you the amps. You can spend $100 or more on a multi-function meter with a clamp on amp meter, or since I already had an expensive mutli-meter without clamp on amps, I happened to find a single function clamp on amp meter for about $40. I'll get the make and model number tonight from home.

Robert

[DONNIE]

Now THATS impressive. I too want to know how you determined amps and volts.

Donnie

(BTW.......I stole a copy of your spreadsheet)

OOP's too slow.

[JohnT]

I would think your payback on a smaller or two-speed pump would be very quick.

[mas985]

With a simple amp meter, you are neglecting the power factor. This is caused by amps getting out of phase with the voltage. Typically, power factors for motors are about 90% so you can subtract about 10% off of that bill.

The most accurate way to measure your power is to use the electric meter on the side of your house since that is what the power company uses. Each meter is a bit different but a call to your electric service or web site will show you how to convert to kwh.

[Rangeball]

If you know the amp rating of a particular motor, can you calculate the cost just from that?

What's the forumula you'd use?

I have a 12 amp motor, run it 24/7, and looking at my last bill I pay $.083 per KWH.

[JohnT]

If you know the amp rating of a particular motor, can you calculate the cost just from that?

What's the forumula you'd use?

I have a 12 amp motor, run it 24/7, and looking at my last bill I pay $.083 per KWH.

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.

[JohnInSoCal]

thanks for 220 then do I add the 2 legs together to get the total amps ?

[JohnT]

thanks for 220 then do I add the 2 legs together to get the total amps ?

No, just one.