Mars M12804 Motor Run Capacitor 4 Mfd 440V

Product Description

The MARS M12804 is a round motor run capacitor rated at 4 microfarads (MFD) and 440 volts, designed for continuous-duty operation in single-phase AC motors found in HVAC equipment. Motor run capacitors stay energized throughout the motor's run cycle, maintaining the phase shift needed to keep auxiliary windings operating efficiently. The M12804 is a direct-replacement component typically installed by licensed HVAC technicians during routine maintenance or motor replacement service calls. Its round form factor suits the most common capacitor mounting configurations in residential and light-commercial equipment.

This capacitor is suited for use with single-phase PSC (permanent split capacitor) motors in condensing units, air handlers, and evaporator coil fan assemblies. It is a common service-replacement part stocked by HVAC technicians for field repairs when a weak or failed run capacitor is identified as the cause of motor starting problems, overheating, or reduced motor efficiency. The 440-volt rating provides a standard safety margin above the 370-volt systems common in residential HVAC, making it a versatile replacement option across a range of equipment.

Key Features

• 4 MFD capacitance for precise phase-shift support in PSC motor circuits
• 440-volt rating accommodates both 370V and 440V motor applications
• Round case design fits standard capacitor mounting brackets and straps
• Continuous-duty construction for year-round operation in condensing and air handler units

Compatibility

Designed as an OEM-style replacement motor run capacitor for single-phase PSC motors in residential and light-commercial HVAC condensing units and air handler fan assemblies requiring a 4 MFD 440V round capacitor.

Installation Notes

Motor run capacitors are installed by licensed HVAC technicians. Disconnect and lock out all power to the unit before handling any capacitor — capacitors store a lethal charge and must be safely discharged before removal. Verify that the replacement MFD rating and voltage rating match or exceed the original equipment specification before installation. Follow all applicable local codes and manufacturer wiring diagrams when reconnecting terminals.

Technical Specifications

• Capacitance: 4 MFD
• Voltage Rating: 440 volts
• Case Shape: Round
• UPC: 685744128045

Standard Information

• Brand: MARS
• Manufacturer Part Number: M12804