Carrier KR11AZ506 Blower Pulley

When you're out in the field servicing a Carrier, Bryant, or Payne air handler or rooftop unit, ensuring the blower system maintains precise airflow is non-negotiable. The Carrier KR11AZ506 Blower Pulley is a Factory Authorized Part designed to hold exact tolerances. This single-groove pulley features a 4 3/4-inch outer diameter (OD) and a 5/8-inch bore, specifically engineered for power transmission within commercial and residential belt-drive assemblies. Constructed from high-strength steel, this blower pulley (also referred to as a sheave) supports 4L, A, and B groove belts, providing the consistent drive ratio needed to prevent motor overload or inadequate CFM. Whether you are performing a replacement for a seized sheave or addressing HVAC blower pulley maintenance, using an OEM part like the KR11AZ506 ensures the keyway and set screw seat perfectly on the motor shaft, reducing vibration and premature belt wear. This is a direct replacement for Carrier part number KR11AD516 and is a standard component in 48HCD and 48HCE series units.

• Precise 4.75" OD: Maintains the factory-set drive ratio to ensure the blower spins at the intended RPM for proper air balance.
• Steel Construction: Provides superior durability compared to cast-iron alternatives, resisting stress under high-torque starts.
• Universal Belt Compatibility: Designed to fit 4L, A, and B section V-belts for versatile application across various HVAC systems.
• Secure Fitment: The 5/8-inch bore is machined to tight tolerances for easy sliding onto the shaft while preventing axial movement once the set screw is torqued.

Is the KR11AZ506 an adjustable-pitch sheave?
No, this is a fixed-diameter blower pulley. If you need to change the blower speed to adjust for external static pressure, you will typically adjust the motor sheave, not this driven pulley.

What should I check if I see black dust around the pulley?
Black rubber dust usually indicates a misalignment between the KR11AZ506 and the motor pulley. Use a straightedge to ensure the grooves are perfectly aligned and check that the belt tension is within manufacturer specs.

Does this pulley include the set screw and keyway?
Yes, this OEM replacement features the standard keyway and includes the technical set screw required to lock the pulley onto the 5/8" blower shaft.

This item is not eligible for free shipping.

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.