OEM Carrier High Pressure Switch 448#OPN / 327#CLS for Model TFACCY50DK480311

This is the genuine OEM factory-replacement high pressure switch for the Carrier TFACCY50DK480311 commercial packaged/rooftop unit. The high pressure switch (HK02ZA442) is a critical refrigerant-side safety device that monitors refrigerant circuit pressure and opens the circuit when pressure exceeds the safe threshold — protecting the compressor from catastrophic damage. When this switch fails or trips due to age, vibration, or refrigerant overcharge, you'll typically experience nuisance high-pressure lockouts, compressor short-cycling, or a system that trips on manual reset repeatedly without an apparent refrigerant-side fault. A second OEM switch, HK02ZB044, serves as the low pressure switch on this platform (7#OPN / 22#CLS, 50" leads) and is also stocked for this model.

• Specs (HK02ZA442 — High Pressure Switch): 448 PSI opening pressure | 327 PSI closing pressure | OEM factory-matched setpoints | Replaces HK02ZA439
• Specs (HK02ZB044 — Low Pressure Switch): 7 PSI opening pressure | 22 PSI closing pressure | 50" leads | 24V | Country of Origin: Mexico
• OEM vs Generic: Genuine Carrier OEM switches are calibrated to exact factory pressure setpoints (±tolerance), ensuring no nuisance trips and full compressor protection. Aftermarket switches often drift from spec, risking either unprotected operation or false lockouts.
• Install Difficulty: 3/5 — Requires refrigerant-side work. Always recover refrigerant per EPA Section 608 before replacing. Tools needed: manifold gauges, refrigerant recovery unit, 1/4" flare fittings, multimeter. Verify system pressures are within normal range before condemning the switch.
• Warranty: 1-year OEM factory warranty. Ships same business day from our warehouse when ordered before cutoff.

Compatibility: Engineered as the direct OEM replacement for Carrier TFACCY50DK480311. Both OEM part numbers — HK02ZA442 (high pressure, primary) and HK02ZB044 (low pressure, secondary) — are in stock. Always verify pressure setpoints on your unit's data plate and wiring diagram before ordering. Need help confirming fitment? Our HVAC parts specialists verify compatibility before you buy — contact us today and we'll ship your order out fast.