Harmonic Problems and UPS Solution for Computer Installation

Computers installations small or big are susceptible to harmonics in the power lines. The advance designs of computer and peripherals make them virtually failure proof. But in presence of low quality power, containing harmonics brings down the life of equipment and subject them to premature failure. All the standard measuring instruments of Ac current, voltage, power, … Read more

Why can’t an Induction Motor run at synchronous speed?

The induction motor can’t run at synchronous speed because it is not possible to run the motor without load. Even the motor is at no load, there would be core loss,copper loss and air friction loss.In a nut shell, the motor slip can not be zero in any case. Therefore, running of induction motor at … Read more

What is the slip value of a 3-phase induction motor at synchronous speed and starting speed?

When the stator of the induction motor is fed three phase supply, the synchronous rotating field is generated. The flux generated in the stator gets linked to the rotor conductor. The voltage is induced in the rotor if the relative speed difference exist between the synchronous speed(Ns= 120f/P) and the actual rotor speed. The difference … Read more

The resistance of L length wire is R. If half of its length stretch such as the total length becomes 2L what will be the final resistance?

The resistance of L length wire is R. The resistance of L/2 length wire is R/2 Now the other L/2 length of the wire is stretched to length X to have full length of conductor 2L L/2 +X = 2L X= 3/2 L The length of the stretched conductor is 1.5 L. Length of conductor … Read more

What is the difference between 0.2 and 0.2S class CT?

The metering class current transformer is used for metering the energy for revenue purposes. Therefore, the metering class current transformer must be as accurate as possible for correct metering of the energy. The metering class current transformer is used for tariff metering application.   As per IEC/AS standard, the metering class current transformer is available … Read more