OEM Carrier High Pressure Switch 406/300 PSI — HK02ZA395 for Model PH1PNA018000AABA

The Carrier HK02ZA395 is the factory-specified OEM high pressure switch for the PH1PNA018000AABA packaged heat pump unit. This safety switch continuously monitors refrigerant pressure on the high side of the refrigeration circuit. When system pressure exceeds the cut-out threshold, the switch opens to de-energize the compressor, protecting it from catastrophic damage caused by overcharge, blocked airflow, or a failing condenser fan. A faulty high pressure switch will often trigger nuisance high-pressure lockouts, prevent the compressor from starting, or cause the system to fault out on a pressure trip code even when actual system pressures are normal.

• Specs: Opens (cut-out) at 406 PSI | Closes (cut-in) at 300 PSI | 240 VAC rated | 1/8" NPT male thread | Sensata PS80-03-0018 platform | Cross-reference: HK02ZA395A
• OEM vs Generic: This is a genuine Carrier Factory Authorized Part, precision-calibrated to ±1% of rated trip point. Aftermarket switches frequently drift in setpoint, leading to either nuisance trips or, worse, failure to protect the compressor at true over-pressure conditions.
• Install difficulty: 2/5 — Recover refrigerant and depressurize the system fully before removing the switch. Tools needed: manifold gauge set, adjustable wrench, refrigerant recovery machine, multimeter (to verify continuity before reinstall). Always apply thread sealant to the 1/8" NPT fitting — never use Teflon tape near refrigerant circuits.
• Warranty: 1-year OEM factory warranty against defects in materials and workmanship. In-stock and ships same business day from our warehouse.

Compatibility: Designed as a direct OEM replacement for Carrier model PH1PNA018000AABA packaged heat pump systems. Also cross-references to superseded Carrier part numbers 312926-217, 71267D1, HK02ZA380, HK02ZA396, and others — verify against your unit's data plate and service manual before ordering. Our HVAC specialists are available to confirm fitment before you buy.