Power Factor Correction

A three-phase balanced load draws a line current of 80 A at 0.90 lagging power factor. Solve the minimum size in kVAR of the capacitor bank needed to raise the power factor to 0.95 leading, if the line to line voltage is 13,200 volts.

Two Y-connected, 50° rise induction motors are fed by a 4160 V, line to line, 3-phase 60 Hz motor-control center 20 feet away. Motor #1 drives a 600-hp compressor. The efficiency of this motor is 90% and its power factor is 0.5. Instruments of motor #2 indicate 1730 kW, 277 amperes. Determine the capacity in microfarads per phase of a wye-connected bank that is required to correct the power factor of the total load to 0.966 lagging.

A 2.3 kV three-phase system supplies a 120-kW, 0.6 pf lagging balanced load. Determine the capacitance in each phase of a wye-connected capacitor bank to adjust the power to 0.90 lagging.

A single-phase, 60 Hz, 5 hp squirrel cage induction motor draws a current of 53 A at 117 V. If it has a 78.5% electrical to mechanical conversion efficiency, what capacitance should be connected at the terminals of the motor in order to increase the power factor of the load combination to 92%?

A three-phase, 60 Hz, 2200 volts induction motor develops 500 HP, 0.8 lagging pf and efficiency of 94%. The power factor is raised to 0.90 lagging by connecting a bank of condensers in delta across the lines. If each of the capacitance unit is built up of four similar 550 V condensers, calculate the required capacitance of each condenser.

A star-connected 400 Hp (metric), 2000 V, 50 c/s motor works at a power factor of 0.7 lagging. A bank of mesh-connected condensers are used to raise the power factor to 0.93 lagging. Calculate the capacitance of each unit required if each is rated 500 V, 50 c/s. The motor efficiency is 85%.

A factory draws a lagging load of 2000 kW at a power factor of 60% from a 6 kV bus line. A synchronous capacitor is installed to raise the overall power factor to unity. Assuming the synchronous capacitor losses are 275 kW, calculate the operating power factor of the synchronous capacitor.

A 400-V three-phase balanced load takes 40 A at a lagging power factor of 0.8. An over-excited synchronous motor is connected to raise the power factor to unity. If the mechanical output of the motor is 15 hp and its efficiency is 85%, find the kVA input to the motor.

A three-phase load of 100 kVA operates at 0.707-pf lagging. Solve for the operating power factor of a synchronous condenser necessary to raise the system power factor to 0.866 lagging, and so arrange that the system apparent power is the same as before the correction.

An industrial plant has an electrical load of 5000 kW at 80% pf lagging. It has been decided to replace a 500-hp induction motor that drives a pump. This motor operates at an efficiency of 90% and a pf of 0.9 lagging. If a synchronous motor is purchased as a replacement, which is capable of operating at 0.80 pf leading. What will be the new plant pf. Assume the synchronous motor to have the same efficiency.

A synchronous motor is drawing 60 kW is connected in parallel with a load drawing 250 kW at a lagging power factor of 0.8. If the combined load has a power factor of 0.9, at what power factor is the synchronous motor operating?

An inductive load consumes 10 kW at 0.75 pf lagging. A synchronous motor with a pf of 0.9 leading is connected in parallel with the inductive load. What is the minimum required kW size of the synchronous motor so that the combined load will have a pf of 0.8 lagging.

An industrial plant draws 500 kW at 0.6 power factor from a 3-phase system. In order to raise the power factor to 0.866 lagging and to supply needed additional power, a synchronous motor is added. This motor draws 300 kW bringing the new total plant load to 800 kW. Neglecting the losses of the synchronous motor, calculate its exact required kVA rating.

An induction motor load of 1500 kW consists of several units in parallel, operating at an average power factor of 0.80 lagging. In order to improve the power factor, a portion of the induction motor loads is to be replaced by a synchronous motor, operating at the same efficiency as the induction motors and at a power factor of 0.70 leading. Find the kVA rating of the synchronous motor required bringing the power factor of the total load to 0.90 lagging. Assume the induction motor load, which has to be replaced, operates at the same pf as the induction motor group.

An alternator rated 530-kVA, is operating at 0.60 pf lagging. A synchronous condenser is in parallel to improve the pf to 90% lagging. Determine the operating power factor of parallel synchronous condenser. Assume the alternator is not supposed to be overloaded.

An over-excited synchronous motor is connected across a 150 kVA, 0.70 lagging power factor load. The motor takes 12 kW while running on no-load. Calculate the kVA rating of the motor required in order to bring the overall pf of the motor-inductive load combination to unity.

An industrial load takes 250 kW at 60% pf from a 600 V, 60 Hz, 3-phase feeder. It is desired to raise the pf of the entire feeder to 90% by means of a synchronous motor, which at the same time is to drive a dc compound generator, requiring that the synchronous motor takes 70 kW from the line. Determine the required current rating of the synchronous motor.

An existing industrial plant has an average load of 900 kW at 0.6 pf lagging. To raise the overall power factor to 0.92, a synchronous motor driving a DC generator is to be installed. If the input of the synchronous motor will be 250 kW, calculate its kVA input rating.