Why two transformers and that too identical are needed in this test?

Both transformers are connected to supply such that one transformer is loaded on another. Primaries of the two identical transformers are connected in parallel across a supply. Thus input power measured by wattmeter W1 is equal to iron losses of both transformers. i.e. iron loss per transformer Pi = W1/2.

Why do we need 2 transformers?

In most cases, frequency is irrelevant to the proper operation of the appliance. Where frequency is an issue – such as with clocks, stereo components, and timers – the appliance must have both a transformer to adjust voltage, and physical adjustment of gears, pulleys, etc. to correct the speed of operation.

Which test is sufficient for efficiency of two identical transformers under load conditions?

Which test is sufficient for efficiency of two identical transformers under load conditions? Explanation: Open circuit test and short circuit test collectively gives the value of all parameters of an equivalent circuit of a transformer.

Why Sumpner test is carried out?

Sumpner’s test: The maximum temperature rise in a large transformer is determined by the full load test by measuring the temperature of their oil after every particular interval at a time. The full load test on a small transformer is very convenient, but on the large transformer, it is very difficult.

Why is there a need at times to connect transformers in parallel What are the important considerations when doing this?

The transformers are connected in parallel when load on one of the transformers is more than its capacity. The reliability is increased with parallel operation than to have single larger unit. The cost associated with maintaining the spares is less when two transformers are connected in parallel.

Why indirect testing of a transformer is necessary?

Open circuit & Short circuit test is also known as the Indirect Test. Performance of a transformer can be determine without any actual loading at any load and power factor by open and short circuit test. This test are very economical because power require is very less to perform this test.

When two identical transformers are available then the best method of finding their efficiency under load condition is?

When two identical transformers are available, then the best method to find their efficiency under load conditions is the test.

What will happen if two transformer are connected in parallel with unequal impedance?

Same Polarity The transformers should be properly connected with regard to their polarity. If they are connected with incorrect polarities then the two emfs, induced in the secondary windings which are in parallel, will act together in the local secondary circuit and produce a short circuit.