OEM Carrier Single Run Capacitor 4 MFD 370V for Model PY2PNB042090AB

This OEM single run capacitor is the factory-specified replacement for the Carrier PY2PNB042090AB packaged unit. The run capacitor maintains the precise phase shift needed to keep the motor running smoothly after startup. When this component fails, you'll typically notice the compressor or fan motor humming but not spinning, or the unit tripping on thermal overload shortly after attempting to start. Left unchecked, a weak or failed run capacitor accelerates motor winding damage and can lead to a costly compressor replacement.

• Specs: 4 MFD (microfarad) ± 5% | 370 VAC rated | Oval case | 50/60 Hz | OEM Totaline/Carrier part numbers P291-0403 and P291-1503 (15 MFD 370V, fan motor circuit) — verify your data plate before ordering
• OEM vs Generic: OEM capacitors are manufactured to Carrier's exact tolerance specifications. Generic units frequently run outside ±5% MFD tolerance, causing premature motor stress, increased current draw, and shortened equipment life.
• Install difficulty: 2/5 — Always discharge the capacitor fully before handling terminals. Tools needed: 1/4" nut driver, insulated needle-nose pliers, multimeter with capacitance mode. Photograph all wiring connections before disconnecting. Follow all local electrical codes and shut off power at the disconnect before beginning.
• Warranty: 1-year OEM factory warranty against defects. Ships same business day from our warehouse when ordered before 3 PM local time.

Compatibility: Designed for Carrier model PY2PNB042090AB packaged units. Note that P291-1503 (15 MFD 370V) is the companion fan motor run capacitor for the same unit and has been superseded by P291-1504. Always match the MFD rating and voltage to your unit's data plate before installing. Our fitment team is available to verify compatibility before you order — no guesswork required.