The Trane IS20126-4000 (also CNT03666, 1324040502) is a precision-engineered pressure switch used in HVAC systems to monitor airflow or pressure differentials. Rated at 0.15" Water Column PF, this low-pressure switch is essential for maintaining operational safety and performance in commercial rooftop and packaged systems. Key Features OEM-quality Trane part for system compatibility and performance Accurate 0.15" WC set point for low-pressure applications Compact and durable design Supports pilot duty at 28 VA Reliable operation for enhanced safety and efficiency Specifications Model Numbers: IS20126-4000, CNT03666, 1324040502 Type: Air Pressure Switch Set Point: 0.15" Water Column PF Electrical Rating: 28 VA, pilot duty Application: Low-pressure monitoring in HVAC units Compatible Models YSC120F4EXA YSC120F3RYA YHC120F3RHA0LP0C0A2A000A0B000E YSC120FWELA YSC120F3EXA YSC120A4ELA YSC090AWELA YSC102A4EHA YSC072AWELA YSC092A4RHA Why Choose This Item Choose the Trane IS20126-4000 pressure switch for assured compatibility and dependability in your Trane system. Designed for optimal control of airflow and safety, this pressure switch ensures that your HVAC unit operates within ideal parameters?preventing system failures and costly repairs. Trusted by professionals, it's a smart replacement for original Trane installations.