540-648 uF/MFD 110-125 VAC Round Start Capacitor

Key Features

• Capacitance: 540-648 microfarads (uF/MFD)
• Voltage Rating: 110-125 Volts AC
• Frequency: 50/60 Hz
• Dimensions: 1 13/16 in. Diameter x 4 3/8 in. Height
• Terminals: 1/4 inch male quick-connect
• Construction: Non-polarized aluminum electrolytic
• Case: Hermetically sealed bakelite case resists oil, dirt, and moisture
• Duty Cycle: Intermittent, for motor starting applications

Replaces / Cross-Reference Part Numbers

• Packard PMJ540A
• BMI 091A540B125CE7A
• UPC 840899105864

Compatibility & Fitment

• Application: Designed for starting single-phase AC motors
• Common Usage: Air conditioners, refrigeration units, compressors, furnace fan motors, and other motor-driven equipment
• Fits applications requiring a 540-648 MFD capacitor rated for 110V, 115V, or 125V systems

When to Replace

• Motor hums but does not start
• Slow or difficult motor startup
• Circuit breaker trips when the motor attempts to start
• Existing capacitor shows physical damage like bulging, cracking, or leaking fluid
• Capacitance measures outside the rated tolerance when tested with a multimeter

Installation Tips

• Disconnect all electrical power to the unit before servicing.
• Safely discharge the old capacitor using a suitable resistor across the terminals.
• Ensure the microfarad (uF/MFD) rating matches the original capacitor's specification.
• The new capacitor's voltage rating must be equal to or higher than the original.
• As a non-polarized capacitor, wires can be connected to either terminal.
• Secure the capacitor in its mounting bracket to prevent vibration.