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# Why does short circuit test essentially show copper losses and not excitation losses in a transformer?

## Why does short circuit test essentially show copper losses and not excitation losses in a transformer?

Why does the short-circuit test essentially show only I²R losses and not excitation losses in a transformer? Because the test is conducted with a primary voltage that is low enough to not cause significant excitation loss. The voltage is usually just enough to get full rated current into the short circuited secondary.

## Why the iron losses are neglected in a short circuit test of a single phase transformer?

Since the applied voltage Vsc is short circuitvoltage in the transformer and hence it is quite small compared to the rated voltage, so, we can neglect the core loss due to the small applied voltage.

Why does open circuit test give core losses while short circuit test gives copper losses?

Open circuit or No load test on Transformer Usually high voltage (HV) winding is kept open and the low voltage (LV) winding is connected to its normal supply. And as the other side of transformer is open circuited, there is no output power. Hence, this input power only consists of core losses and copper losses.

### Which losses are negligible in this test short circuit test and why?

2. During short circuit test why iron losses are negligible? Explanation: Very small amount of voltage is given to the transformer primary thus the magnetic losses which are dependent on magnetic flux density will get minimum value, hence iron losses are negligible.

### What is the purpose of short circuit test?

The purpose of a short-circuit test is to determine the series branch parameters of the equivalent circuit of a transformer.

Why short circuit test is performed on HV side?

During the test a lower value of voltage is applied than the rated value so that rated current should flow in the winding. As the rated current is lesser on HV side as compared to the LV side, it is convenient to conduct the test on the HV side so that the meters used for the test are oflower range.

## Why iron losses are not in short circuit test?

Iron losses in short circuit test are not absent they are just neglected. Because in the short circuit test the LV winding is short circuited which means high currrent and low voltage in the secondary side. Copper loss are dependent on the current but not on voltage.

## Why does iron losses are negligible during short circuit test?

Now during the short circuit test, the iron losses of a transformer is negligible because the voltage applied across the H.V side is a small fraction of the rated voltage and so mutual flux is small. Therefore Iron losses also small fraction which is negligible compared to copper losses.

Why is an open circuit test and short circuit test performed?

The open circuit and short circuit test are performed for determining the parameter of the transformer like their efficiency, voltage regulation, circuit constant etc. These tests are performed without the actual loading and because of this reason the very less power is required for the test.

### Why iron losses are negligible during short circuit test?

Which loss is determined by conducting short circuit?

The purpose of conducting a short circuit test is to determine the winding resistance, reactance, and the copper loss of the transformer.