MARS 12903 Run Capacitor

The MARS 12903 is a professional-grade 3 MFD 370 VAC oval run capacitor engineered for continuous motor support in residential and light commercial HVAC systems. As a critical component for optimizing motor efficiency, this single-section capacitor provides the necessary phase shift to maintain consistent torque and reduce amperage draw during operation. The 3 microfarad rating is precisely calibrated for small blower motors and specific fan applications where stable capacitance is mandatory for long-term reliability. Encased in a ruggedized aluminum housing, the MARS 12903 features an internal physical interrupter as a safety mechanism, ensuring the circuit breaks in the event of an internal failure. This HVAC replacement capacitor is rated for 50/60 Hz and operates within a temperature range of -40°C to 70°C. Whether you are performing a preventative maintenance swap or a reactive service call, this oval motor capacitor serves as a direct drop-in for 370V applications, offering 60,000 hours of operational life for demanding field conditions.

• High-Reliability Design: Rated for 60,000 hours of operational life, ensuring consistent 3 MFD 370 VAC output for critical motor circuits.
• Enhanced Safety: Features a built-in physical pressure interrupter and non-PCB oil for safe operation under extreme thermal conditions.
• Universal HVAC Compatibility: Standard oval geometry fits most OEM mounting brackets in furnaces and air handlers.
• Optimized Performance: Maintains strict capacitance tolerances to maximize motor efficiency and reduce energy consumption.

What happens if I use a 370V capacitor on a 440V system?
A capacitor must never be used in a system with a voltage higher than its rating. While a 440V capacitor can replace a 370V unit, using a 370 VAC capacitor on a 440V circuit will lead to immediate dielectric breakdown and premature component failure.

Can the MARS 12903 be used for both 50Hz and 60Hz systems?
Yes, this unit is dual-rated for 50/60 Hz frequencies, making it a versatile choice for standard North American grids and international applications requiring 3 microfarad capacitance.

Does the orientation of an oval run capacitor matter during installation?
The MARS 12903 can be mounted in any orientation. However, technicians should ensure it is securely strapped to the housing to prevent vibration-induced lead fatigue or cabinet noise.

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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.