Re: Utility Billing KWH/ Measures in KVA but bills in kWh

James Sweet wrote:
>> The standard kwh meter used in all residential and commercial
>> customers is able to measure the real power directly.  Customer
>> loads do *not* have to be power-factor corrected.  If that were
>> true, every freezer case in a grocery store would have to have pf
>> correction on the compressor and every office-building would have pf
>> correction on the A/C (not to mention the flourescent lighting).
>>
>> daestrom
>>
>
>
> Most do! All but the cheapest fluorescent ballasts are HPF, they have
> an internal capacitor to correct the power factor. I've never seen an
> A/C compressor that didn't have it as well. True, it won't affect the
> bill for home users, but it's still always good to aim for as close
> to unity power factor as possible, it allows circuits to be fully
> utilized and reduces losses in the wiring.

The cap in A/C compressors isn't for pf, it's a capacitive start motor. 
Same in refridgerators, wa****ng machines, dryers, and many furnace motors.

Commercial three-phase compressors used in refridgeration and A/C do *not*

have any capacitors for pf-correction.  The 3-phase motors are started 
directly across the line.  (well, new hi-efficiency units sometimes use 
variable speed control, but that's another story).

I don't disagree that it's a 'good idea', but the previous poster 
"ItsASecretDummy" made some outlandish statements about having to pay for 
non-pf corrected loads.  The obvious proof that he's way-off base on this
is 
that most industrial motors are not pf-corrected and you don't have to 
'register' or have them inspected by the utility before installation.

daestrom