Water Pump Electrical Usage

25 January 2003

I am trying to come up with a “guesstimate”/approximate figure for typical monthly electrical usage to run a water pump for a pressure tank. I know that it is not a large amount, depends on usage but need a figure for an explanation to give a small claims court judge in a Landlord/Tenant suit. I’ll try to explain situation.

This is in a duplex, 2-unit rental on one acre in southern Michigan. One unit has 1 full bath and the other has 2 full baths, a water softener and a dishwasher. Also had 2 clothes washers and an underground sprinkler system in the front yard covering 15,000 sq ft (4 zones w/ 3-4 heads) which may have run daily this past summer (3 months). Additional lawn watering in other areas by traditional sprinklers. Occupants in the building were 2 women, 2 teenage girls and 1-2 other occasional people.

The pump is submersible type and believed drilled to about 160 ft to hit water. I can not find any literature to give you more details. The pressure tank is a Well-Rite Series Diaphragm, 33 gal capacity, model #WR120-04. Water-saving aerators were on some of the fixtures and all 3 toilets were low 1.6 gal per flush

This building has 1 well, 1 pump and 1 tank. I need to get an idea of how much money one tenant pays for all the water in the building. . I think the former tenant may feel that water tank w/ submersible pump was creating high electric bills-I think it was her 2 window AC units.

I am guessing in the summer w/ lawn water it was approximately $10 a month for the whole building and maybe $5.00 the other months at $0.08 a KW. What do you think?

I am thinking that the pump probably is no larger than ¾ horsepower. With 1 horsepower=746 watts, that’s ¾ hp=560watts. Then, 0.560 X $0.08 (1 KW)=$0.045 per hour. That’s 4.5 cents an hour-less than a nickle. Then calculate # of hours pump ran.

Also, is the 560 watts per actual, accumulated 6o minutes that the pump is running (between cut-in and cut-out) or is it clock time, say noon to 1:00. Pumps, furnaces and others do not run continiously-they come on and off.

Thank you for your time.

 

I am not going to fig it out but I think you are probably right and lots of those are 1/2 hp so your fig of 3/4 hp is probably good. 2 window units going full blast would certainly use considerable power.

 

You have done a great job so far.
Tha caculation you would use is.
Cost = Watts x Hours Used x Rate Per Hour / 1000
To be fair devide that into the people using it.

Watts = Volts x Amps

Hope this helps....