Question 524Electricity & Electronics - QMED
70% to passIn an ungrounded distribution system, as compared to a normal indication, what is the indication on a switchboard of a current carrying conductor making an accidental electrical contact with a wiring metal conduit?
Areading of 1.0 on the power factor meter
Blower switchboard wattmeter reading than normal
Ctotally darkened switchboard ground detecting light
Dhigher switchboard voltmeter reading than normal
AI Explanation
The correct answer is C) totally darkened switchboard ground detecting light. In an ungrounded distribution system, if a current-carrying conductor accidentally makes contact with a metal wiring conduit, it will cause a ground fault. This ground fault will result in the switchboard's ground detecting light becoming totally darkened, as there is no path for the ground fault current to return to the system. The other options are incorrect because: A) A ground fault would not affect the power factor reading. B) A ground fault would not cause a lower wattmeter reading, but rather an abnormal reading. D) A ground fault would not cause a higher voltmeter reading, but rather an abnormal reading.
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