Question 442Electricity/Electronics - QMED70% to pass
When troubleshooting a motor controller, all indications are that a relay coil should be energized. If there was no magnetic pull, with rated voltage measured across the coil, what would be the most probable cause?
AI Explanation
The correct answer is D) the coil is open.
If the rated voltage is measured across the relay coil, but there is no magnetic pull, the most probable cause is that the coil itself is open or disconnected. This means the coil winding has been broken or interrupted, preventing the flow of current required to energize the coil and actuate the relay.
The other options are less likely in this scenario. A) the control fuse is open would result in no voltage reaching the coil. B) an auxiliary contact in series with the coil being defective would still allow voltage to the coil. C) the relay armature being stuck would not prevent the coil from generating magnetic pull if it was properly energized.
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