Step 1
Switch off the power, and disconnect the freezer from the power supply. Make sure the power cannot be reconnected to the appliance while you are working on it.
Step 2
Access the rear of the freezer, and look for a cylindrical object connected to thin pipes. This is the compressor; it may look similar to a pressurized gas cylinder. Locate the manufacturer's plaque attached to the compressor, and read the "Maximum wattage" information.
Step 3
Substitute the maximum wattage and the appliance voltage into Ohm's Law to determine the starting current. Ohm's Law, often expressed as I = P/V, where I is the current, P is the power in watts and V is the voltage, states that the current equals the wattage divided by the voltage. For example, a 720-watt compressor running on 120 volts draws a starting current of 6 amps: 720/120 = 6.