Page 102 - CITS - Electrician - Trade Practical

ELECTRICIAN - CITS

4 Check the connections and ensure that auto transformer knob in zero position..
5 Switch ON the supply and slowly increase the voltage in auto transformer until LV side ammeter reads rated
full load current of transformer.
6 Record readings of voltmeter, ammeter and watt meter.
7 Switch OFF the supply and disconnect the transformer and meters

Tabular column:

Voltage Current Watts Total loss
(V) (I) (W)

OC Test to measure
iron losses (WI) W = W + W C
I
T
SC Test to measure
copper losses (WC)

Safety precautions:
1 Do not make loose & wrong connections.
2 Do not apply more voltage while conducting SC test.

3 Check the voltage range of watt meter before switching ON the circuit .
4 While conducting SC test do not short the LV terminals for long time, it may overheat and damage the
transformer.

85

CITS : Power - Electrician & Wireman - Exercise 42