Lennox 81G51 Motor

The Lennox 81G51 is a high-performance, single-phase HVAC blower motor designed for reliable air circulation in residential and light industrial applications. Operating at 208/230V, this 1/2 HP motor delivers a steady 825 RPM, providing the torque necessary to maintain consistent static pressure within the ductwork. As a direct OEM replacement motor, the 81G51 is identical to the Lennox 81G5101, ensuring a drop-in fit with no modifications required to the mounting brackets or electrical leads. Built on a 48 frame chassis with an open enclosure, it features a 5.6-inch body diameter and a 1/2-inch x 2.5-inch shaft, making it compatible with a wide range of Lennox blower assemblies. This PSC motor utilizes sleeve bearings for quiet operation and longevity in horizontal mounting positions. To ensure peak performance and protect the internal windings from overheating, technicians should verify that the associated 20µF 370VAC run capacitor is within spec during installation.

Key Benefits for HVAC Contractors:

• Universal Voltage Compatibility: Operates efficiently on both 208V and 230V single-phase power systems.
• Seamless Integration: Direct cross-reference for Lennox 81G5101 saves time on-site by eliminating the need for universal mounting kits.
• Optimized Airflow: The 825 RPM output is specifically calibrated for Lennox air handlers to maintain proper CFM across the evaporator coil.
• Reliable Construction: Features a robust steel frame and sleeve bearings designed for continuous duty in climate control systems.
• Multiple Speed Taps: Includes 3-speed functionality to fine-tune system performance based on specific ductwork requirements.

Common Questions:

What is the correct capacitor for the Lennox 81G51?
This motor requires a 20 MFD / 370 VAC run capacitor for proper startup and operation. Using an undersized or failing capacitor can lead to motor humming or premature failure.

Can I use the 81G51 to replace an 81G5101?
Yes, the 81G51 and 81G5101 are electrically and physically identical parts, sharing the same 1/2 HP rating, RPM, and frame size.

What is the rotation direction for this part?
The 81G51 is typically configured for CCWLE (Counter-Clockwise Lead End) rotation, which is standard for most Lennox blower wheel orientations.

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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.