reasonable estimate for power factor

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Is it reasonable to use an estimate of .9 pf for a typical restaurant with lots of fractional horsepower motors for refrigeration, 6-8 larger HVAC motors (1-2.5 HP), and fluorescent lighting throughout - all using HF electronic ballasts?
 

Smart $

Esteemed Member
Location
Ohio
I was thinking .85 being a more reasonable estimate, but I have no solid basis, just a SWAG.

Is there a purpose?
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
Is it reasonable to use an estimate of .9 pf for a typical restaurant with lots of fractional horsepower motors for refrigeration, 6-8 larger HVAC motors (1-2.5 HP), and fluorescent lighting throughout - all using HF electronic ballasts?

Like many such questions, the context in which the question is asked matters a lot.

It is not a reasonable estimate if there is money on the line.

As a guess to an off the cuff question, it is probably OK.
 
purpose/context

purpose/context

Thanks everyone.

The purpose is for a utility load letter. We do our service load calculations in kVA, but the utility wants the calculated load in kW. So a SWAG should be good enough - as long as it's not too 'WA' ;) .
 

Smart $

Esteemed Member
Location
Ohio
Thanks everyone.

The purpose is for a utility load letter. We do our service load calculations in kVA, but the utility wants the calculated load in kW. So a SWAG should be good enough - as long as it's not too 'WA' ;) .
If that's the case, your best course of action is to just tell them kVA = kW... unless it makes a difference in rate.
 

Electric-Light

Senior Member
Induction motors without PF correction? I'd use .8

HF ballasts and single phase PSC HVAC are close enough to unity.
CSIR refrigeration equipment can run pretty low.

The night time power factor can be pretty low when the AC is scheduled off and lights are off. You'll need to observe it for a few days with an energy auditor to get a meaningful average. Ignore the spot readings used by capacitor salesman.
 
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