Dispersion Coefficient of Induction Motor

The power factor and dispersion coefficient of an induction motor have relationship.The smaller the dispersion coefficient the better the power factor. Power factor is an important factor in designing of induction motor. Power factor depends upon two factors:     i) Magnetizing current :A large value of the magnetizing current indicates poor power factor. Magnetizing current is indirectly … Read more

Why is Power Factor of Transformer is Poor at no Load?

The transformer draws no load current from the supply source when its secondary is open circuit.The no load current has two components of current- Magnetization current(Im) and iron loss component current(Iw). The transformer takes magnetization current to set up the magnetic flux in the CRGO magnetic core. The iron loss component of the current caused … Read more

Why an Induction Motor is almost constant Speed Motor?

    An induction motor always runs at speeds just below its synchronous speed. At no load the speed is closest to its synchronous speed. This running speed reduces further when loaded towards its full load capacity , to about 5% for a moderately rated machine to just more than 5% for smaller rated machine. The decreased speed … Read more

Instrument Safety Factor of Current Transformer

  The current transformer is used for measuring the current.The specifications of the measuring class CT is as given below. The Instrument Safety Factor (ISF) is very important parameter for measuring class CT. CTR CT Terminal CT Burden Accuracy Class CT ISF 200/5      1S1-1S2 10 0.5 10 The secondary of the current transformer is connected to ampere … Read more