MARS 12918 Run Capacitor

The MARS 12918 is a high-performance 35 MFD 370V oval run capacitor designed for continuous duty application in residential and light commercial HVACR systems. As a veteran-grade motor run capacitor, this unit provides the necessary phase shift to the start winding of PSC (Permanent Split Capacitor) motors, ensuring efficient operation for compressors and condenser fan motors. Built to EIA-456-A standards, the 12918 features a non-PCB, oil-filled design housed in a rugged aluminum case, capable of operating in temperatures ranging from -40°C to 70°C.

When you are out on a service call, reliability is paramount. The MARS 12918 utilizes a physical interrupter for safety and is a direct 35 uF 370 VAC capacitor replacement for various OEM brands. Its compact oval run capacitor form factor allows for easy installation in tight control boxes, while the 4-spade quick-connect terminals provide maximum flexibility for multiple lead connections without the need for additional piggyback terminals.

Key Benefits

• Universal 35 MFD rating compatible with a wide range of air conditioning and refrigeration equipment.
• Rated for 370 VAC, providing a stable voltage source for start and run cycles.
• Oval shape design facilitates retrofitting in existing mounting brackets and space-constrained cabinets.
• High-grade metallized polypropylene film dielectric ensures consistent capacitance and reduced power loss.
• Meets rigorous Tecumseh H-115 specifications for durability under high-stress electrical loads.

Common Questions

Can I use a 440V capacitor to replace this 370V model?
Yes, you can safely use a 440V rated capacitor as long as the capacitance remains at 35 MFD, as the voltage rating on a capacitor indicates the maximum tension it can handle. However, never swap a 370V capacitor into a 440V system.

How do I know if the MARS 12918 is failing?
Standard indicators include a bulging top, leaking oil, or a capacitance reading outside of the +/- 6% tolerance when tested with a multimeter under no-load conditions.

Does it matter which terminal I use for the common wire?
The four prongs on each terminal are internally connected. You can use any of the four spade positions for your common or start leads, provided you maintain the correct wiring configuration of the original motor circuit.

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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.