An engineer suspects a short in the motor windings has caused the motor to trip on overload. What instrument should be used to check the motor?

Prepare for the New York City Refrigeration License Exam I. Utilize flashcards, multiple-choice questions, and detailed explanations to boost your readiness. Ace your licensing exam!

To check for a short in motor windings, you measure the winding resistance with an ohmmeter. An ohmmeter passes a small current through a winding and reports its resistance, so you can spot a short by seeing abnormally low resistance or a mismatch between windings. If windings are healthy, the resistance will be within the expected range; a short between turns or to another winding will pull that value down, often significantly, and can explain an overload trip. While a voltmeter or ammeter can tell you about supply voltage or current, they don’t reveal the internal resistance of the windings. A multimeter can measure resistance too, but the specialized tool for assessing winding continuity and faults is the ohmmeter.