Packard PMJ189 Start Capacitor

The Packard PMJ189 Start Capacitor is a dry-electrolytic 189-227 MFD 125V round capacitor designed for high-torque motor starting in HVACR and pumping applications. This run-start capacitor provides the necessary phase shift to increase starting torque, efficiently overcoming the inertia of static loads in single-phase motor systems. Encased in a moisture- and oil-resistant phenolic resin housing, the PMJ189 is built to withstand the rigorous duty cycles of heavy-duty compressors and fan motors. Measuring 1-7/16 inches in diameter and 3-3/8 inches in height, this Type II motor start capacitor features dual 1/4-inch male quick-connect terminals for reliable electrical contact. Operating within a temperature range of -40°C to 65°C, it is an ideal exact fit replacement for Mars 11021 and Mallory CSU189125. When diagnosing why a compressor won't start or humming motors, verifying capacitance with a multimeter ensures this 125 Volt start capacitor restores AC motor performance and prevents premature winding failure.

Key Benefits for Technicians:

• High Starting Torque: Effectively bridges the 189-227 Microfarad range to initiate motor rotation under heavy load conditions.
• Universal Compatibility: Physical dimensions allow for seamless integration into standard motor capacitor mounting brackets and enclosures.
• Durable Construction: The phenolic case provides superior insulation and protection against environmental contaminants and mechanical stress.
• Industry Standard Standards: Engineered to meet EIA-463-B specifications for electrolytic capacitors, ensuring reliable 50/60Hz operation.

Common Contractor Questions:

Can I use a higher MFD rating if I don’t have a 189-227 MFD unit?
Maintaining the correct microfarad rating is critical. If the capacitance is too high, the motor winding can overheat; if it is too low, the motor may fail to reach the necessary starting RPM. Always match the MFD range specified by the OEM.

What causes a start capacitor like the PMJ189 to fail prematurely?
Frequent cycling, faulty potential relays, or high ambient temperatures are the primary causes. If the start capacitor remains in the circuit too long after the motor has reached speed, the internal pressure will rise, causing the relief plug to vent.

Is the voltage rating of 125V interchangeable?
You can replace a lower voltage capacitor with a higher one (e.g., swapping a 110V for a 125V), but you must never install a capacitor with a voltage rating lower than the original component.

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.