How to Select a Power Factor Correction Capacitor
The most obvious benefit for correcting and improving power factor in a facility is to reduce utility costs by reducing or eliminating the penalty for a low power factor. Another benefit is that additional loads can be added to the facility for the same installed KVA (transformer) and, in many cases, postpone the need for system additions or upgrades. Capacitor selection is based on the motor’s horsepower, rpm and voltage.
To select the correct capacitor:
Step 1—Determine the motor’s horsepower located under the “HP” column in the Power Factor Correction KVAR chart shown at right. For example, select “40 HP”.
Step 2—Read across the row to select the correct motor rpm. For example, select the “1800 RPM” column. Where the row and column intersect is “12.5”, the suggested maximum capacitor (KVAR) needed to correct the power factor of a 40-HP motor rated at 1800 rpm.
Step 3—Determine the motor voltage and whether you need fused protection. Power fuses are required, per the NEC, if the capacitors are installed on the line side of the motor starter. In the table below, choose the “Select KVAR” dropdown beneath the heading matching your desired Voltage and Protection. Select 12.5 from the “Select KVAR” dropdown. You may now add this item to your cart or click the item number for more details.
WEG low-voltage power factor correction capacitors are designed to help adjust and correct the power factor of loads requiring electricity. They can help prevent overheating and premature motor failure caused by loads with low power factor. By raising the power factor, they can help increase efficiency of equipment, conductors, and motors.