DieselShip's Online Content Library

Q8) (a) State THREE reasons why switchboard instruments are supplied via instrument transformers from the power circuits which they monitor. (3)

(b) Explain why it is hazardous to open circuit a current transformer whilst its primary is still energized. (4)

(c) Sketch a circuit diagram showing an ammeter, a voltmeter and a wattmeter fed from a single-phase supply via current and voltage transfomers. (5)

(d) An ammeter, a voltmeter and a wattmeter monitoring a single phase supply read 40 A, 240 V and 8 kW respectively.

Calculate the power factor of the circuit. (4).