Capacitor
- Thread starter roger62
- Start date
- Status
- Location
- Massachusetts
IF the facility has a poor power factor a capacitor bank can reduce the monthly bills
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
iwire said:
If the utility charges for a poor power factor.
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
I think not. There is current flowing into the capacitor when you first turn things on. The impact they have on a building's overall power factor doesn't take effect until they reach an equilibrium state. That takes about the same amount of time as the motor starting cycle.dmanda24 said:
I think not here as well. I suspect that even if they did significantly reduce motor starting currents, the cost reduction would be no more than pennies per year.dmanda24 said:
drbond24
Senior Member
- Location
- Barboursville, West Virginia
roger62 said:
You've all dodged the original question. The capacitor can alter the power factor, but it does not change the amount of energy you actually use.
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
Not so, says I.
The amount of energy you use includes energy consumed as real power and energy consumed as reactive power. It is a matter of local utility rules as to whether the customer gets charged separately for the two. But if the power factor is low, you are consuming more energy than you would with a higher power factor, and a capacitor can lower the energy consumption.
The amount of energy you use includes energy consumed as real power and energy consumed as reactive power. It is a matter of local utility rules as to whether the customer gets charged separately for the two. But if the power factor is low, you are consuming more energy than you would with a higher power factor, and a capacitor can lower the energy consumption.
drbond24
Senior Member
- Location
- Barboursville, West Virginia
charlie b said:
At least we're addressing the OP now.
I agree that what I said was not correct, but what I was *thinking* when I typed the wrong thing was correct (believe it or not
). Changing the power factor does not alter the REAL power being used. The amount of kW your load requires is the same. However, it does alter the APPARENT power by decreasing the reactive portion of the power triangle. The amount of kVA you are using will decrease.If that is incorrect, I quit for the day. Actually, I quit either way. It's time to go home. :grin:
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
charlie b said:
However 'reactive power' specifically means power that is shuttling back and forth between supplier and load, delivering no energy.
The only energy saved by installing capacitors would be because of second order effects, eg. reduced current flow in feeders, or better transformer regulation supplying a high power factor load.
For convenience, we generally say that an inductive load 'consumes' reactive power, and a capacitive load 'supplies' reactive power...but a load that looks like a big capacitor bank would have a terrible power factor.
-Jon
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