WhisperFlo WF-24 kW draw

[engrav]

Good morning

WhisperFlo WF-24 rated at 1hp, then 746 watts, then would draw .746 kW

Can measure draw by counting beats / seconds on the meter and calculate with the formula
3600 * beats / seconds * kh * multiplier / 1000
where kh is a number from the meter, in this case .6
and multiplier is also a number from the meter, in this case 80

Measured draw is 2.34kW with pump on and 0.35 with pump off
Would seem pump draws 1.99kW


Why would measured draw be so much higher than predicted?

Thank you

 

[JasonLion]

Where did you get 746 watts? That is certainly not correct. I suspect that you used the classic definition of HP to watts conversion. Unfortunately that has nothing to do with modern electric motors. Modern electric motors have essentially fictional HP ratings having to do with marketing and nothing to do with standards like that conversion factor. For that matter there are half a dozen conflicting definitions of HP, and that one has never been one of the popular ones. Actual power used will vary with your plumbing, but should be somewhere more like 1400-1700 watts for that particular pump.

Your power meter approach is generally valid, but subject to a fair amount of imprecision and several places where you could have made mistakes in the math.

 

[engrav]

ah ha
Where from 746? This old house draws lots of kWh so are trying to figure out where is it going. Had a Puget Sound Energy guy out and he went round using 746. Seems so much for that "expert". Will cease and desist on 746.
Thank you.

 

[pooldv]

How about getting a non-contact ammeter to measure current draw?

Here is a random one I found on google for 35 bucks.
http://www.coleparmer.com/Product/E...QpYg68GdbhBY8nSjGX3rA_3TY3NdjAmfPgaAgi68P8HAQ

 

[JasonLion]

While old school HP to watt ratios are no longer fully accurate. But, it is a decent reference for maximum possible current draw. A 1hp pump should/could not draw over 1000 watts, or 1kw.

While it varies dramatically from pump to pump, most 1 HP pool pumps draw more than 1,000 watts. Anywhere from 1,000 watts to 2,300 watts is reasonable for an arbitrary 1 HP pool pump. You really shouldn't expect the nameplate HP rating to mean much, they fudge it all over the place for marketing purposes.

 

[pooldv]

While it varies dramatically from pump to pump, most 1 HP pool pumps draw more than 1,000 watts. Anywhere from 1,000 watts to 2,300 watts is reasonable for an arbitrary 1 HP pool pump. You really shouldn't expect the nameplate HP rating to mean much, they fudge it all over the place for marketing purposes.

Dang it! Back to school for me!!

 

[pooldv]

OK, I visited Pentair's website for a little studying.

WhisperFlo WF-24 part number 011772
1hp, service factor 1.24, service factor hp 1.25
230v Full Load Amps 7.1 is 1,633 watts or 1.63 kW max draw