Tuesday, November 21, 2006

Cheap pumps

Lots of us want to buy cheap pumps from a big box store. While they usually perform as expected, they don't perform as long as more expensive ones. Worse than that, they cost much more per month to operate. The more expensive the pump, normally, the cheaper the operating costs.

Electric costs are easy to compute. I am often asked how much it costs to run a submersible pump and if there is a difference between brands. I will use the example of a 100 watt light bulb and a utility cost of $0.08 per KWH. A KWH is a kilowatt-hour or, 1,000 watts used for 1 hour. A 100 watt light - .1 kilowatt or .1 KWH = less that 1 cent per hour.

• Find the actual wattage used by the motor. (If the actual amp draw is not available, estimate by using the full load amps plate.)

• Watts = volts x amps for single phase motors. The light bulb has an amp draw of 8.7 x 115 volts = 100 watts.

• Compute your cost per month by multiplying the KWH x 24 (hours used per day) x 30 (days used per month) x cost in KWH (to find the actual cost look at your last power bill and divide the total power charges byt KWH used).



2 comments:

Anonymous said...

Uh,oh, we gotta get you in touch with the really big out-of-pond pumps, like Lim Dragon Series.

Unknown said...

I have not used the really big out-of-pond pumps. I would love to learn about them, but dare not write about anything I have not used. Thanks for the tip. I will check them out.