How to avoid low power factor?

As far as possible, over excited synchronous motors have to be used in place of induction motors. High speed induction motors have better power factor than low-speed induction motors. They are smaller in frame size and economical too.  The induction motors have maximum power factor when fully loaded. So we should try use induction motors at full load condition. ...

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What are the causes of low power factor?

Various Causes of Low Power factor: Most of the AC motors are induction motor type. They have low lagging power factor. During light loads the induction motors will work at a power factor or 0.2 to 0.3 and during full load condition they will work at 0.8 to 0.9. Arc lamps, electric discharge lamps and industrial heating furnaces operate at low lagging power factor. Very low lagging power factorof agriculture motor pump set. The load on the power system is varying. It will be high during morning and evening and will be low at other times....

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What are the disadvantages of Low Power Factor?

Low Power Factor Disadvantages: In AC circuits, power consumed depends on the power factor. Thus the power factor plays an important role in AC circuits. For instant, we know that; Power in a Three Phase AC Circuit = P = √3 V x I CosФ And Current in a Three Phase AC Circuits = I = P / (3 V x CosФ) I ∝1 /CosФ….… (1) Also, Power in a Single Phase AC Circuits = P = V x I CosФ And Current in a Three phase AC Circuits = I = P / (V x CosФ) I ∝ 1/CosФ……… (2) It is clear from both equations (1) an (2) that...

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Basic Motor Formulas and Calculations

Here are some  motor formulas that may be useful. Calculating Motor Speed: A squirrel cage induction motor is a constant speed device. It cannot operate for any length of time at speeds below those shown on the nameplate without danger of burning out. To Calculate the speed of a induction motor, apply this formula: Srpm = 120 x F                P Srpm = synchronous revolutions per minute. 120   = constant F      ...

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