Power Factor Correctors

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kcaj

Member
Location
Syosset, NY
A friend in New Jersey contacted me and wanted to know if money could be saved on monthly electric bill for a building used for Curling (main equipment being an ice plant) if a device used to "correct the power factor" were installed. Electric usage is about 103,000 kWH/yr. with heaviest use during 6 winter months, usage drops when the ice plant (3-phase, 208-volts) is shut down. Any inputr would be appricated.
 

jim dungar

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Staff member
Location
Wisconsin
Occupation
PE (Retired) - Power Systems
Only if there is a separate PF 'penalty' charge on their electric bill (it might be called KVAR).
 

charlie b

Moderator
Staff member
Location
Lockport, IL
Occupation
Retired Electrical Engineer
I agree with Jim. Your friend should have a look at the electric utility bill for the facility. Or if that is not available (privacy or security reasons), then call the utility company itself, and ask them about power factor penalties. A large ice plant is likely to have a large motor or two, and there will be money to be saved by increasing the power factor closer to 1.0. But if the rate structure for the local utility does not include extra charges, then the money will be saved by the utility company, not by the facility using the power.
 

mjoneill

Member
Power Factor Correction

Power Factor Correction

I believe you may be in First Energy's service area if you are in the correct part of New Jershey.

FE's rate tariffs are posted on their WEB site and they do have a power factor clase for General Services above simple GS-small. They generally charge for any power factor greater than 80%. Which means they allow your power factor to go to 80% before they charge you for it. Further, if they do charge you for it they only charge for Power Factors correct to 80%. I.E., if your power factor is 75%, you get charged for the 5% difference between 75% and 80%.

If you power factor is greater than that allowed in the tarrif, the power factor correction capacitors could save you some money.

Hope this helps.
 

mwdkmpr

Member
There will be a minor savings if they currently have a poor PF. This will be realized because of the reduced power loss in the wire. PF correction should lower the current flowing in the wire and thus reduce the power loss. Power loss = Current squared x wire resistance.
 

robbietan

Senior Member
Location
Antipolo City
I believe you may be in First Energy's service area if you are in the correct part of New Jershey.

FE's rate tariffs are posted on their WEB site and they do have a power factor clase for General Services above simple GS-small. They generally charge for any power factor greater than 80%. Which means they allow your power factor to go to 80% before they charge you for it. Further, if they do charge you for it they only charge for Power Factors correct to 80%. I.E., if your power factor is 75%, you get charged for the 5% difference between 75% and 80%.

If you power factor is greater than that allowed in the tarrif, the power factor correction capacitors could save you some money.

Hope this helps.

I believe that the electric bill would also contain the average power factor for the billing month. It would greatly help if you could look at how much the pf varies throughout one year before buying pf correctors. having a low pf for one month (and a low penalty) for a single year should make you think twice about getting pf correctors, for example
 

charlie

Senior Member
Location
Indianapolis
There are two misleading items on most power bills to watch out for.
  1. The bill may have the readings in kW and somewhere in the bill there will be a charge for kVA. In switching to kVA, you have the power factor buried in that number. You can reduce kVA with the prudent installation of capacitance but you must do the math to find the actual kVAR needed.
  2. Up to a certain percentage, you are charged for poor power factor. That percentage is usually 80% or 85%. If you look at the actual tariff that is filed with your state's public service commission or governing body, you will normally find a credit given for correcting past the given percentage. In other words, you are really being charged for anything less than 100%.
Does that make me a whistle blower? :)
 
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