Air compressor unloader valves work by releasing air that is trapped in the compressor's pipe and piston once the pressure switch trips the power supply to turn the compressor off. By releasing the trapped air in the piston, the compressor motor is able to start properly. If the trapped air is not released, the compressor's piston remains under pressure, making it difficult for the motor to start.
Trapped air in the compressor piston and pipe increases the load on the electric motor. This can lead to the motor failing to start or the electric motor demanding more amps, which can blow out a fuse or trip a breaker. It is important for an air compressor unloader valve to work properly to ensure that the unit functions normally and safely.
The air compressor unloader valve is often located near the air tank of the unit and is usually part of the pressure switch assembly. Once the air pressure in the air compressor tank reaches a predetermined level, the check valve trips the motor to turn it off, triggering the air compressor unloader valve to open. The check valve keeps the compressed air in the tank and prevents it from being released.