Voltage Drop Testing

If the entire load of 1,000 W is turned on, the voltmeter will read about 113 V, a voltage drop of about 2 V.

A No. 14 gauge wire is allowed 15 A by the electrical codes. In this case, a load of 15 A will cause a voltage drop of about 3.5 V for a 50-ft branch circuit. This still would not be excessive.

With an undervoltage in excess of 10%, trouble can be expected. This would be a voltage of less than 103.5 V in a 115-V circuit.

Excerpt from Refrigeration and Air Conditioning available from the Online Store at RSES, Refrigeration Service Engineers Society, The HVACR Training Authority.

 

 

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