Power Factor Correction

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USMC1302

USMC1302

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NW Indiana
There is a building that has basically been mothballed, unoccupied, with very little in the way of electrical/mechanical loads being used. The building had a PFC bank installed at some point(at the service), but has additional capacitors installed at loads (circulating pumps, etc). The utility bill is showing a power factor of .37, which seems unbelievable with almost nothing running. It doesn't appear any capacitors are switched in. What could cause such a low reading? Thanks

Steve
 
USMC1302 said:
There is a building that has basically been mothballed, unoccupied, with very little in the way of electrical/mechanical loads being used. The building had a PFC bank installed at some point(at the service), but has additional capacitors installed at loads (circulating pumps, etc). The utility bill is showing a power factor of .37, which seems unbelievable with almost nothing running. It doesn't appear any capacitors are switched in. What could cause such a low reading? Thanks

Steve
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Unloaded transformers possibly.
 
140908-1530 EDT

USMC:

If you have a very large bank of PFC capacitors across the line, and very little load in comparison, then you are possibly way over-correcting for power factor.

If so that would cause a low power factor. If power factor does not have an associated sign. then you do not know if PF is leading or lagging.

.
 
Could it also be the manner in which the "measurements" are made? Mr. B, we have had a similar thought on the transformers, and have noted that if we shut down (2) particular transformers, the PF reading jumped back up to .95. I'm not sure how big an issue this is overall until I see the utility bill. It just seemed strange to have the PF registering that low.
 
.35 leading or lagging? Makes a difference. Leading usually means capacitors or LONG unloaded underground runs. Lagging usually means unloaded transformers. Either way, it's wasting current, which may cost money if the utility bills for reactive power. My bet is the method of measurement.
 
That's about right for transformers with next to nothing on it. What was your kWh usage?


USMC1302 said:
Could it also be the manner in which the "measurements" are made? Mr. B, we have had a similar thought on the transformers, and have noted that if we shut down (2) particular transformers, the PF reading jumped back up to .95. I'm not sure how big an issue this is overall until I see the utility bill. It just seemed strange to have the PF registering that low.
Click to expand...

What are they powering? Do you have a reason to leave them on?
 
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