CARRIER COMFORT SERIES CENTRAL AIR CONDITIONER General Troubleshooting

High-Efficiency HVAC Air Filter

A clogged filter increases static pressure and restricts airflow across the evaporator coil, causing the refrigerant to remain at a lower temperature and pressure. This leads the low-pressure switch to detect a potential coil-freeze condition, triggering a safety shutdown of the compressor circuit to prevent mechanical damage.

Low Pressure Cut-Out Switch

This electromechanical sensor is the physical component responsible for interrupting the compressor's operation when suction-side pressure falls below the factory set point. In many cases, the internal bellows or diaphragm of the switch fails or loses calibration, causing it to trip prematurely or cycle rapidly during the initial pressure drop at startup.

Dual Run Capacitor

The capacitor maintains the phase-angle shift required for the compressor's motor windings to run efficiently. When capacitance drifts out of tolerance, the motor generates excessive waste heat, eventually tripping the internal bimetallic thermal overload protector, which cuts power to the motor until it cools enough to reset, creating a persistent start-stop loop.