Page 102 - CITS - Electrician - Trade Practical
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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