Utility Billing KWH/ Measures in KVA but bills in kWh

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How does the utility determine the Kilowatts for the kwh energy charge, if the standard meter measures KVA. Would 100 KVA for one hour record 100 kWh? Does a meter have a built in pf correction factor?

Thanks/Clyde

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A *domestic* meter measures actual power consumption and displays it in kWhr.

-- Sue

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TEST

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This is an industrial meter, measuring demand (KVA) and KWH. Medium sized industrial plant.

Thks/Clyde

Pal>> How does the utility determine the Kilowatts for the kwh energy charge, if

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You will have either a kWh meter + a peak KVA demand meter, or the two will be combined in a single instrument which will read both the actual kWh used (as in a standard watthour meter) as well as the peak KVA during the billing period. The peak reading part will have a lag (typically 15-30 minutes) to reach the actual value) so that it doesn't respond to short term peaks such as motor starting which have little effect on equipment ratings. Older KVA meters simply had a pointer (with thermal lag) which pushed another pointer leaving it at the peak position to be reset by the meter reader). The meter does not need to read power factor.

Example: 2400kWh/day

a) constant load of 100kW at unity pf --- supply rated at 100kVA capacity b)same load, power factor 0.6 or net 166kVA supply needs to be 66% larger c)same load, unity pf but concentrated for 8 hour of the day. 300kW =300kVA supply required

The energy charge as read by the kWh part of the meter is the same in all cases but there is an additional charge based on the peak demand kVA reflecting the cost of the supply equipment.

Your bill "should" indicate both the energy charge and the demand charge as separate components as this is useful information. It may bias the energy charge by some demand factor which is less useful.

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But the standard meter doesn't measure KVA. It measures kWhr directly.

Yes. The meter is pf sensitive so it only responds to 'real' power (kW) and because it uses a set of gearing to move the dials, it also integrates the power over time to give you kilowatt-hours.

daestrom P.S. Of course many newer meters are electronic now instead of electro-mechanical. But the measurements are the same.

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Especially the modern, digital versions.

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Why make a sane post, and then follow it with this retarded horseshit?

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TOP POSTING IDIOT!

OK, chump... here goes...

ALL business and industrial service MUST pay for ALL non-PF corrected loads.

The meter is not corrected, you equipment must be. That means that any and all inductive loads that you use WILL cost you a bit more.

How can you possibly know the difference between WATTS and VARS, and not know what that difference really amounts to or whom it would be applicable to?

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Wrong assumption. Residential meters measure kWh. PF is built into the measurement.

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You are so far off it is funny.

The only folks that get billed for having a bad pf are large industries with very low pf.

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

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If the meter claims to read kWh, then you can take it to the bank that it does in fact read kWh. Most revenue meters are able to measure the real power being used directly without external pf correction. Tariffs for industry often require additional metering if there is unusual load connected. Very low pf can be an issue because of the impact on system voltage. The possibility of high, short-term demand often incurs an additional tariff where you have to pay based on the highest 'peak' during a billing cycle. It sounds like this is what you have.

daestrom

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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.

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The meters do not get corrected, idiot. The LOADS do!

No shit, dumbfuck. That is what I said.

Why don't you just make shit up as you go, DaeTurd?

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The cap in A/C compressors isn't for pf, it's a capacitive start motor. Same in refridgerators, washing 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

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No, you said:

TOP POSTING IDIOT!

OK, chump... here goes...

ALL business and industrial service MUST pay for ALL non-PF corrected loads.

The meter is not corrected, you equipment must be. That means that any and all inductive loads that you use WILL cost you a bit more.

You claim that meters are not able to sense the pf so the customer is required to correct loads. Nothing could be further from the truth.

It would seem you can't write a cogent thought without resorting to profanity. Why don't you go read a couple of tariffs and learn something besides new four-letter words.

Here is a nice explaination of demand charges. Notice that it discusses the peak power levels (demand) and the energy charges. It doesn't discuss pf-correction or charges for pf.

Here is the tariff that National Grid of NY works under. Have a nice read. Be sure to search for 'power factor' and find all the places where it says customers have to correct their equipment (you won't find it).
If you knew anything about revenue metering you'd know that kw-hour meters automatically respond to only the true power used. A 1.0 kW load at unity power factor makes the dial spin just as fast as a 1.25 kVA load at 0.8 pf or a 2.0 kVA load at 0.5 pf.

Sorry you can't accept reality, but that's not my problem.

daestrom

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Well I measured the power factor of my 3 ton heat pump and found it to be .85 to .91 depending on compressor load, so the capacitor may not be for PFC, but I'd still consider it to be HPF.

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This is a typical value for a small motor that is properly sized for its load. Really *large* motors can be as high as 0.95. But you don't find many such motors (>2000 hp) except in industry :-).

daestrom

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That's because your motor is sized to the compressor properly. If you pulled that motor off the load (compressor) it would have a lousy PF. It is not "PF corrected" in any way.

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If you knew anything about it, you would know that power companies REQUIRE their industrial customers to correct power factors on loads that present high pf differentials.

And if you knew a goddamned thing about it, you would know that that is exactly why they take steps to get paid for what gets used, not what is read on the meter.

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