How to Test the Amp Draw of a Refrigerator Compressor

Refrigerators and freezers are responsible for about 17 percent of all the electricity used in American homes, according to the California Energy Commission.
Apart from the light, the fridge compressor uses all the power.Apart from the light, the fridge compressor uses all the power.
The compressor is the most power-hungry component in a refrigerator. Apart from the internal light, the compressor may be the only component drawing current. Testing the amp draw is a straightforward process requiring the ability to use a current meter and to read a digital display. Knowing the amp draw may help with household budgeting.

Step 1

Gain access to the point where the power cord connects to the refrigerator. If the conductors are bundled with other wires, separate one conductor wire and keep it isolated. Currents flowing though wires running in close proximity to the one under test may influence your readings.

Step 2

Set a clamp-on ammeter to "auto-range" or to the appropriate current range if auto-range is not available. Open the clamp jaws by depressing the "Open" button. Place one conductor from the refrigerator cord between the jaws and close them gently, positioning the conductor in the center of the jaws.

Step 3

Observe the display on the meter. It may take a few seconds to register a reading. With the compressor switched off, the reading will be very low. Wait until the compressor turns on, and observe the new reading. Subtract the original reading from the second reading to find the current drawn by the compressor.

Things You Will Need

  • Clamp-on ammeter

About the Author

David Robinson has written professionally since 2000. He is a Fellow of the Royal Geographical Society and the Royal Meteorological Society. He has written for the "Telegraph" and "Guardian" newspapers in the U.K., government publications, websites, magazines and school textbooks. He holds an honors Bachelor of Arts in geography and education and a teaching certificate from Durham University, England.