Mars 12791 – Jard Dual Run Capacitor, 50/7.5 MFD, 440V, Round Case
The Mars 12791 capacitor, manufactured under the Jard brand, is a dual-section motor run capacitor engineered to operate both compressor and condenser fan motors in HVAC systems. Rated at 50/7.5 microfarads with a maximum voltage of 440 VAC, this capacitor is built for continuous duty in residential and light commercial applications.
Constructed with metallized polypropylene film in an oil-filled aluminum case, it ensures dependable electrical performance under thermal and mechanical stress. The cylindrical case supports standard ¼" quick-connect terminals for simplified wiring and integration into existing systems.
Technical Specifications
Model: Mars 12791 (Jard series)
Capacitance: 50/7.5 µF ±5%
Voltage: 370/440 VAC
Frequency: 50/60 Hz
Operating Temperature Range: -40°C to +70°C
Enclosure: Round aluminum case
Safety Feature: Pressure-sensitive interrupter
Terminal Type: ¼" male quick-connect
Application: PSC motors in HVAC condenser units
Performance and Application
Designed for use in systems requiring support for both fan and compressor motors
Suitable for split system air conditioners and heat pump condensers
Maintains electrical stability under high-load and continuous-duty conditions
Ideal for systems that operate across fluctuating line voltages
Installation Overview
This component should be installed by a licensed HVAC technician to ensure proper sizing, safe handling, and code compliance. Key considerations include:
Confirm system compatibility prior to installation
Disconnect power and discharge existing capacitor before replacement
Observe terminal labels and wiring diagrams for proper lead placement
Inspect mounting hardware and secure the capacitor using manufacturer-approved brackets
Contractor-Focused Benefits
Dual-section design reduces the need for multiple capacitors in shared motor systems
High voltage rating accommodates systems operating near or above nominal 370V
Oil-filled aluminum case promotes thermal dissipation and corrosion resistance
Compact form factor allows installation in tight compartments