Question 185Electricity/Electronics - 1st Asst/Chief70% to pass
As shown in figure "A" of the illustration, if in troubleshooting the control circuit using on-line techniques with a voltmeter with the start button depressed and the following readings are taken, what is the problem? "X1" to "X2" reads 115 VAC; "1" to "X2" reads 0 VAC; "2" to "X2" reads 0 VAC; and "3" to "X2" reads 0 VAC. Illustration EL-0123
AI Explanation
The correct answer is B) the fuse is blown.
The reasoning is as follows:
With the start button depressed, we would expect to see 115 VAC on the control circuit if it were operating properly. However, the readings show 115 VAC at the input ("X1" to "X2"), but 0 VAC at all the other points ("1" to "X2", "2" to "X2", "3" to "X2"). This indicates that the circuit is not being energized, likely due to a blown fuse.
The other options are incorrect because an open-circuited secondary winding (A) or open-circuited stop button (C) would not result in the same voltage readings, and the start button being open-circuited (D) would prevent the circuit from being energized at all.
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