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Power Factor Correction

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Low power factor is expensive and inefficient. Some utility companies begin to charge a penalty if your power factor drops below a certain level. Low power factor also reduces your electrical system’s distribution capacity by increasing current flow and causing voltage drops. Excessive voltage drops can cause overheating and premature failure of motors and other inductive equipment. We can help you improve your power factor and reduce electric bills while enhancing your electrical system’s capacity.

Invite us out for a free consultation. Electrical Systems, Inc. will inspect your facility and after we monitor your power systems efficiency, we will present you with a report and graphs to help you better understand our findings. We will identify issues and help you implement power factor improvement measures and get you on the right track to saving money and reducing your energy consumption.

What is Power Factor?

Power factor is an indicator of the health and efficiency of your power distribution system. It is the ratio of working (active) power (watts or kilowatts - kW) to apparent power (volt ampere or kilovolt ampers - KVA); or it can also be defined as the ratio of the current drawn that produces real work to the total current drawn from the source or supplier of the energy, such as the electric utility.

Power factor (pf) =
 Active Power
Apparent Power
 Power factor is an indicator of how much of a facility power system’s capacity is available for productive work.

What are Some of the Things that Can Cause Poor Power Factor?

Any non-linear loads can impact your power factor. Such as:
  1. Non power factor corrected fluorescent & HID lighting fixture ballasts (40-80% pf)
  2. Arc welders (50 -70% pf)
  3. Solenoids (20 - 50% pf)
  4. Induction heating equipment (60 - 90% pf)
  5. Small “dry-pack” transformers (30-95% pf)
  6. Induction motors (55-90% pf)


What are the Benefits of Improving Power Factor?

  1. Your utility bill will be smaller. Many utilities have power factor incorporated in some form in their rates. They may bill your demand in KVA or have credits and debits depending on your power factor. The utility has to provide distribution facilities, transformers, etc based on your Total Apparent power. The beer mug analogy is a great way to understand this. You order a mug of beer. You pay for a full mug. You really want more beer than foam. With your power bill you could be paying for a lot more “foam” if your power factor is not high.
  2. You can increase your internal electrical system’s capacity. Uncorrected power factor will cause increased losses in your electrical distribution system and limit capacity for expansion.
  3. Voltage drop at the point of use will be reduced, or improved. Voltages below equipment rating will cause reduced efficiency, increased current, and reduced starting torque in motors. Under-voltage reduces the load motors can carry without overheating or stalling.


What Can You Do To Improve Power Factor?

  1. Explore replacement of existing motors with more energy efficient ones with higher power factor.
  2. Specify and use high power factor lighting ballasts. 
  3. Assure that motors are properly sized for their application and duty cycle.
  4. Install capacitors: their leading power factor counterbalances the inductive lagging power factor. For maximum system benefit the capacitors should be located as close as possible to the offending equipment.


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Electrical Systems Inc.