Using this Supco 3 - in - 1 product is very easy. First, make sure your compressor is of the right voltage (220 - 240VAC) and power (1/2HP, 500 - watt). Then, turn off the power supply to your fridge or air - conditioner. Remove the old relay, overload, and capacitor. Install the new Supco unit in place, using the included rubber compressor mounts. It should take only a few seconds. When using, always ensure the power is stable to avoid damage. If you notice any abnormal noises or the compressor doesn't start properly, turn off the power immediately and check the connections. For maintenance, keep the unit clean and dry. Periodically check the rubber mounts for wear and tear. With proper use and maintenance, this product will serve you well for a long time.