Copeland 940-0140-08 Potential Relay

The Copeland 940-0140-08 Potential Relay is a critical OEM compressor start component designed to manage the start-up cycle of high-torque single-phase motors. Operating at a nominal 290 VAC rating, this relay leverages the back EMF generated by the motor's start winding to precisely time the removal of the start capacitor from the circuit. With a calibrated pick-up voltage range of 340-360 VAC and a drop-out voltage of 50-100 VAC, it ensures the motor overcomes initial inertia without internal damage or excessive heat buildup. As an essential HVAC motor starter, it maintains system reliability by preventing electrical faults and optimizing performance in refrigeration and air conditioning units. Its compact, durable housing is built for the rigors of industrial compressor control, providing technicians with a high-accuracy solution for 60 Hz service. Integrating this Copeland motor relay into your repair or maintenance protocol ensures that the start winding is efficiently isolated once peak operating speed is achieved.

• Ensures consistent compressor motor start-up by precisely monitoring back EMF for reliable circuit switching.
• Provides high-performance voltage regulation with a specific 340-360 VAC pick-up range to protect internal windings.
• Reduces electrical stress on start capacitors, extending the functional lifespan of the entire HVACR system.
• Features a rugged design engineered for 290V industrial and commercial refrigeration applications.
• Facilitates a smoother motor transition from start-up to run cycle, minimizing mechanical vibration and wear.

What are the pick-up and drop-out specifications for this relay?
The Copeland 940-0140-08 is calibrated for a pick-up voltage between 340V and 360V, with a drop-out voltage range of 50V to 100V, ensuring accurate timing for 290V systems.

Is this potential relay compatible with universal HVAC applications?
While often used in Copeland compressors, many technicians use this as a direct OEM replacement or cross-referenced part for specific high-torque single-phase motor configurations requiring these exact voltage parameters.

Can this relay help solve compressor starting issues?
Yes, if a motor is struggling to start or tripping breakers due to start-winding issues, replacing a faulty heavy-duty potential relay is a standard diagnostic step for restoring proper HVAC start-up cycles.

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.