How to Test a Copeland KAG2 0075 Lab 800 Compressor

Turn off the power to the compressor unit from the breaker box.

Use the Phillips-head screwdriver to remove the compressor cover retaining screws and then lift the cover of the unit. Set the screws aside in a safe place.

Locate the three terminals on the front top section of the compressor. They will be labeled "C," "R" and "S."

Turn the multimeter on and switch it to the "Resistance" or "Ohms" setting.

Check the continuity between the C and R terminals, the C and S terminals and the R and S terminals with the meter by placing a meter lead to each terminal. The continuity should be around 30 ohms of resistance. If the resistance reading between the terminals is a lot higher than 30 ohms and the unit is cool to the touch, the compressor is bad.

Lay the metal tip of the screwdriver across the leads of the capacitor to discharge it if there is any charge in it.

Read the capacitance rating of the capacitor. It will be clearly marked on the capacitor and it is measured in microfarads.

Switch the multimeter to the capacitance setting. Place the positive lead of the meter to the capacitor's positive terminal and the negative meter lead to the capacitor's negative lead. If the reading on the meter is different from the rating marked on the capacitor, it means the capacitor is bad and needs to be changed.