MARS 12909 Run Capacitor

The MARS 12909 is a professional-grade 12.5 microfarad 370Vac oval run capacitor designed for continuous duty in residential and light commercial HVACR equipment. Engineered as a high-reliability component for permanent split capacitor (PSC) motors, this single-section unit facilitates smooth motor startup and maintains optimal running torque for condenser fan motors and small compressors. This capacitor is a field-proven direct replacement for 39232D008 and 97F9003, ensuring a seamless fit in existing mounting brackets without requiring modification.

Constructed with a durable aluminum case, the MARS 12909 run capacitor features a non-PCB, oil-filled dielectric and a patented internal pressure-sensitive interrupter (PSI). This safety mechanism is designed to disconnect the capacitor in the event of an internal fault or end-of-life pressure buildup, protecting the motor and surrounding circuitry. With a standard 12.5 uF MFD rating and 370 volts capability, it handles 50/60 Hz frequencies and operates efficiently within a temperature range of -40°C to +70°C. The four 1/4-inch male quick-connect terminals allow for straightforward wiring in high-density control boxes.

• Universal Compatibility: Serves as a versatile drop-in HVAC replacement part for multiple OEM brands, including GE/Genteq, Armstrong, and Jard.
• Enhanced Safety: Built-in pressure-sensitive interrupter meets UL and CSA safety standards for fail-safe operation.
• Optimized Performance: Maintains strict ±6% capacitance tolerance to ensure consistent motor efficiency and reduced heat generation.
• Industrial Construction: Corrosion-resistant aluminum housing protects internal components in demanding outdoor environments.

Can this 370V capacitor replace a 440V capacitor?
No. While a 440V capacitor can replace a 370V unit, you must never install a 370V capacitor like the MARS 12909 in a system rated for 440V, as this will lead to premature failure.

What are the physical dimensions for mounting?
This oval run capacitor typically measures approximately 2.875 inches in overall height with a base width of 2.056 inches, making it ideal for compact electrical enclosures.

How do I know if my capacitor is failing?
Common indicators include a "bulged" or swollen top, fluid leakage, or the motor "humming" but failing to start. A multimeter test should confirm if the 12.5 MFD rating has significantly drifted.

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.