Posts Tagged: diagnose variable displacement compressor
How To Diagnose a Variable Displacement AC Compressor
Variable Displacement AC Compressor Problems and Fixes Quick Summary A variable displacement AC compressor adjusts cooling by varying the piston stroke, not by cycling the clutch on and off. In other words, this clutchless compressor runs all the time and “de-strokes” when cooling isn’t needed. The compressor control valve regulates the piston stroke length. The valve is a pulse-width-modulated (PWM) solenoid that allows or restricts refrigerant flow to the advance or retard side of the swash plate. The pulse width is determined by the HVAC control head based on the … Read More
How a Variable Displacement AC Compressor Works
How to Diagnose Variable Displacement Compressor Issues Quick Summary A variable displacement AC compressor adjusts its output based on cooling demand—it doesn’t just turn on and off like clutch-type AC compressors. • A variable displacement compressor changes piston stroke using a swash plate angle instead of cycling like older systems • A compressor control valve is the key component that regulates output and varies the swash plate and piston stroke. • These compressors run continuously but can “de-stroke” to near zero output (free-wheeling). • Most failures I diagnose involve the … Read More