MARS 12790 Run Capacitor

The MARS 12790 dual run capacitor is a heavy-duty 50/5 MFD 440V round capacitor designed for high-performance HVACR motor and compressor applications. This dual-rated component provides the necessary capacitive phase shift for both the compressor and the condenser fan motor, ensuring efficient start-up and lower running amperage. Built to EIA-456-A standards, it features a metallized polypropylene film dielectric housed in a rugged aluminum casing. The 50+5 uF 440 volt rating makes it a universal replacement for 370V and 440V systems, offering increased dielectric strength and thermal stability. With a temperature rating of -40°C to +70°C, this MARS 12790 50/5 MFD 440VAC unit is engineered for continuous duty in demanding environments. The quad-blade quick-connect terminals allow for rapid field installation, while the 440-volt rating provides a superior safety margin against voltage spikes compared to lower-rated 370V capacitors.

Key Technical Benefits

• Dual-Rated Performance: Consolidates a 50 MFD compressor lead and a 5 MFD fan lead into a single round-case footprint.
• Universal Voltage Compatibility: Rated at 440VAC to replace both 370-volt and 440-volt dual run capacitors effortlessly.
• Internal Safety Interrupter: Designed to disconnect the capacitor in the event of an internal pressure buildup.
• Environmentally Safe: Non-PCB oil-filled construction ensures compliance and safe operation across commercial and residential sites.
• Corrosion Resistance: High-grade aluminum housing protects the internal metallized polypropylene film from moisture and oxidation.

Common Contractor Questions

Can I use a 440V capacitor to replace a 370V unit?
Yes, using a 440V round dual run capacitor to replace a 370V unit is a standard practice and often preferred because the higher voltage rating provides a better tolerance for line voltage fluctuations.

How do I identify the correct terminals for wiring?
The MARS 12790 uses standard industry markings: 'C' for Common, 'HERM' for the compressor (50 MFD), and 'FAN' for the condenser fan motor (5 MFD).

What causes a 50/5 MFD capacitor to bulge or fail?
Failure is typically caused by high ambient temperatures, excessive voltage spikes, or motor winding degradation. Replacing a bulging unit immediately is critical to prevent compressor motor burnout.

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.