Carrier KR11HZ218 Sheave

The Carrier KR11HZ218 is a heavy-duty, single groove cast iron sheave designed for precision airflow management in commercial HVACR systems. Featuring a 6.55 inch outside diameter and a 1 3/8 inch fixed bore, this component is engineered to withstand the high-torque demands of industrial blower assemblies and condenser fan motors. The variable pitch range of 4.9 to 6.4 inches allows technicians to fine-tune belt-driven fan speeds, ensuring optimal static pressure and system balancing. Constructed from high-tensile cast iron, this adjustable motor pulley provides superior vibration dampening and heat dissipation compared to stamped steel alternatives. It is a direct OEM replacement sheave for Carrier and Bryant air handling units, ensuring exact alignment and reduced belt wear when used with compatible A or B section V-belts. For contractors performing HVAC pulley maintenance, this sheave offers a reliable solution for precisely calibrating airflow to meet site-specific requirements.

Key Technical Benefits

• Precision Tuning: The 4.9-6.4 variable pitch adjustment allows for granular control over blower RPM and CFM delivery.
• Durable Construction: Cast iron build resists warping and provides a stable rotational mass for high-duty cycle applications.
• Direct Compatibility: Standard 1 3/8" bore and keyway ensure a secure fit on many common motor shaft configurations.
• Reduced Maintenance: Machined grooves minimize friction and extend the service life of drive belts.

Common Technical Questions

How do I adjust the pitch on the KR11HZ218 for higher CFM?
To increase fan speed and airflow, move the adjustable flange closer to the fixed flange by rotating the threaded hub. This increases the effective pitch diameter, causing the belt to ride higher in the groove.

What belt sizes are compatible with this sheave?
This single groove sheave is designed to work with standard 4L, A, 5L, or B section V-belts, providing flexibility for various drive configurations.

Does this sheave require a separate bushing?
No, the KR11HZ218 features a fixed 1 3/8" bore with a standard keyway and set screw, eliminating the need for additional tapered bushings during installation.

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.