Open Circuit Test | Short Circuit Test

Why is the transformer tested?

To find out the efficiency of the transformer, it is necessary to know the amount of core loss and copper loss The open circuit is tested to find out the core of the transformer, and the short circuit is tested to find out the copper loss.

Rules for Open Circuit Test and Short Circuit Test: - 

Rules for Open Circuit Test: -

The test which is done by placing the measuring instrument on the primary side with the secondary winding of the transformer open is called Open Circuit Test. In this case, the high voltage is kept open and the instrument is fitted at low voltage.

What we get by doing open circuit test: -

1.Core Loss,

2.No Load Current,

3.Magnetizing Current,

4.Working current,

5.Core Loss Resistance,

6.Core Loss Resistance,

Rules for short circuit test:-

A short circuit test is done by shorting one side of the transformer and supplying very low voltage to the other side with variac help. This test usually involves shorting the low voltage site This circuit has to supply rated current and connect equipment on the high side. It supplies (5-10%) of the rated voltage.

 What we get by doing short circuit test: - 

1.Short ckt current,

2.Short ckt Voltage,

3.Copper Loss,

4.Equivalent Resistance,

5.Equivalent Reactance,

6.Power Factor,

7.Efficiency and Regulation