OEM Carrier High Pressure Switch HK02ZA442 for Model PY1RPA048115AAWB

This OEM high pressure switch (part number HK02ZA442, with companion low pressure switch HK02ZB044) is the factory-specified replacement for the Carrier PY1RPA048115AAWB packaged rooftop unit. The high pressure switch continuously monitors refrigerant pressure on the high side of the refrigeration circuit. When discharge pressure exceeds the trip point, the switch opens to cut power to the compressor, protecting it from catastrophic damage. Common failure symptoms include nuisance lockouts, compressor short-cycling, or a system that trips on high pressure fault codes even when refrigerant charge and airflow appear normal — often indicating a faulty switch rather than a true over-pressure condition.

• Specs — HK02ZA442 (High Pressure Switch): Opens at 448 PSI | Closes at 327 PSI | Factory-calibrated trip point | Replaces HK02ZA439
• Specs — HK02ZB044 (Low Pressure Switch): Opens at 7 PSI | Closes at 22 PSI | 50" lead wires | 24V control circuit rated
• OEM vs Generic: OEM switches are calibrated to exact factory trip-point tolerances, critical for proper compressor protection. Aftermarket switches often carry wider pressure tolerances that can allow nuisance trips or, worse, fail to protect the compressor at true over-pressure events.
• Install Difficulty: 2/5 — Recover refrigerant before replacing any refrigerant-side pressure switch. Tools needed: manifold gauges, 1/4" flare wrench, multimeter for continuity verification. Always confirm wiring polarity and lead routing before reconnecting. Nitrogen-pressure-test the port fitting before recharging.
• Warranty: 1-year OEM factory warranty. Ships same business day from our warehouse when ordered before 3 PM local time.

Compatibility: Engineered for Carrier model PY1RPA048115AAWB packaged rooftop unit. Both OEM part numbers — HK02ZA442 (high pressure) and HK02ZB044 (low pressure) — are available individually or as a set. Verify the failed switch type (high vs. low side) using your unit's wiring diagram before ordering. Have questions about fitment? Our HVAC parts specialists confirm compatibility before you buy — add to cart or call us today. In stock — ships today.