Powerfactor
- Thread starter JdoubleU
- Start date
- Status
ptonsparky
Tom
- Occupation
- EC - retired
Are you charged for poor power factor? If not, nothing.
brian john
Senior Member
- Location
- Leesburg, VA
What type of building?
How old are these lights?
How are you measuring pf?
what is the pf with lights off?
Are you sure your meter is connected properly, incorrect connections will screw the pf drastically.
They are 3 years old. The lights are t5s and I haven't seen the ballasts. The powerfactor jumps up to the 80s. We have a meter hook up to the Main. Its a very good meter but it might be hooked up inproperly. I am going to hook up a power quality meter and compare the two. Let say the powerfactor is bad, What are someways to correct this?
zog
Senior Member
- Location
- Charlotte, NC
Correction caps, but are you paying a penalty?
Electric-Light
Senior Member
I believe all commercial install ballasts are required to be HPF. Uncorrected electronic ballasts have a PF of 0.5 or so and there is not much you can do about correcting their power factor.
Residential use only and screw-in CFLs usually have a PF of 0.5 to 0.6. Commercial use ballasts are 0.9+, with modern active PFC types getting in excess of 0.995. They're so close to unity that you can assume V*A = W.
Find the relevant regulations requiring high power factor ballasts, then go after the installer to replace all the ballasts at their expense.
The poor power factor is caused by high VA/W caused by non-linear current draw and power factor capacitor won't fix it.
Even if you're not penalized for power factor, you're wasting the potential of existing wiring and transformers. 10kVA transformer can more or less supply 10kW of modern HPF lights, but only 5kW or so of non power factor corrected and if there are motors on the same transformer, they may get pissed at high THD.
If the ballast is rated 120-277v, disconnect one and plug it into a Kill-A-Watt meter plugged into a 120v outlet and check the power factor.
Residential use only and screw-in CFLs usually have a PF of 0.5 to 0.6. Commercial use ballasts are 0.9+, with modern active PFC types getting in excess of 0.995. They're so close to unity that you can assume V*A = W.
Find the relevant regulations requiring high power factor ballasts, then go after the installer to replace all the ballasts at their expense.
The poor power factor is caused by high VA/W caused by non-linear current draw and power factor capacitor won't fix it.
Even if you're not penalized for power factor, you're wasting the potential of existing wiring and transformers. 10kVA transformer can more or less supply 10kW of modern HPF lights, but only 5kW or so of non power factor corrected and if there are motors on the same transformer, they may get pissed at high THD.
If the ballast is rated 120-277v, disconnect one and plug it into a Kill-A-Watt meter plugged into a 120v outlet and check the power factor.
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