Carrier HK02ZA439 Pressure Switch

The Carrier HK02ZA439 Pressure Switch is a high-pressure safety cutout designed for precise refrigerant circuit monitoring in Carrier, Bryant, and Payne condenser units. Engineering specifications confirm a cut-out pressure of 426 PSI and a cut-in pressure of 320 PSI, ensuring the compressor is protected from thermal overload and system blockages. This SPST high-pressure switch features a 1/4-inch female Flare nut connection with a schrader depressor for fast field installation. Built for R-410A high-pressure applications, this encapsulated pressure switch replaces legacy HK02ZA429 and HK02ZA423 models. Using this OEM HVAC replacement part maintains the UL certification of the equipment while ensuring the condensing unit pressure settings remain within manufacturer tolerances. The HK02ZA439 426-320 switch is critical for HVAC compressor protection, preventing catastrophic failure during high ambient temperature spikes or restricted airflow conditions.

• Factory Calibrated Precision: Fixed 426 PSI open and 320 PSI close settings eliminate the need for field adjustments and reduce callbacks.
• Enhanced Durability: The hermetically sealed design prevents moisture ingress and contact oxidation in harsh outdoor environments.
• Direct OEM Compatibility: Ensures exact fitment for Carrier HK02ZA439 specifications, integrating seamlessly with existing control boards and wiring harnesses.
• System Reliability: Rapid response times protect scroll and reciprocating compressors from extreme high-side pressure conditions.

Is the HK02ZA439 compatible with R-22 systems?
No, this switch is specifically calibrated for the higher operating pressures of R-410A systems. Using this on R-22 equipment will result in the system failing to trip at the correct safety thresholds.

Does this switch require a manual reset?
This is an automatic reset pressure switch. Once the high-side pressure drops below the 320 PSI cut-in point, the internal contacts will close, allowing the contactor coil to re-energize.

What is the primary cause of this switch tripping?
Repeated tripping of the 426 PSI high-pressure limit typically indicates a dirty condenser coil, a failed outdoor fan motor, or a refrigerant overcharge within the system.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.