Question

The following result were obtained on a 50KVA transformer

O.C test

Primary voltage = 3300V

Secondary voltage = 415V

Primary power = 430W

S.C test

Primary voltage = 124V

Secondary current = 15.34A

Primary power =525W

Calculate

The efficiency of full load and half load for 0.7pf

The voltage regulation for pf 0.7

1) Lagging

2) Leading

The secondary terminal voltage corresponding to 1&2