Pool pump power consumption and power factor

koxta

0
Aug 24, 2017
9
Northwestern Indiana
Hi guys,

I'm considering swapping out my good old single speed Hayward pump for something more energy efficient (dual or variable speed). As I was trying to figure out my wattage and cost calculations, I noticed that the actual wattage of my pump seemed way off, compared to what's stated on the label. The label reads 2HP, 115V, 16A - so it should be drawing about 1.8kW, whereas my house energy monitor and kill-a-watt both report a number closer to 1kW. I checked the power factor, and it read ~0.55, which would explain the difference between ~1kW and ~1.8KVA. However, I always thought that it's the other way round - the wattage would be consistent, and the KVA would increase proportionally to the inverse of power factor due to increased KVAR. Most websites usually clock 2HP pumps at much higher wattage than the "measly" 1kW I'm getting, so I'm a bit puzzled.

Now, since I am a residential customer, I do not get billed per KVAh, but per KWh used. My question is - is the power factor at this pump/outlet a function of the outlet, wiring, the pump itself, or combination thereof? What I'm trying to figure out is if I should assume a similar power factor in my calculations after a pump replacement? Or will power factor go inadvertently up, thus reducing the cost benefit of getting a newer pump?

I hope someone can clarify this for me.
 
16A I think would be the starting surge. Running power draw is less and is a function of how much head loss is in your system (how hard the pump is working to turn at its constant speed).

Roughly: a 2-speed pump running on hith would be the same as your single speed pump. On low (half speed), the power usage should be about 1/3-1/4 as on high speed. VS pumps are a little more efficient and can run at even lower speeds.

Look for the spreadsheets from mas985 as they will allow you to compare pumps.
 
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