York S1-028-12361-700 Pulley Variable

The York S1-028-12361-700 Pulley Variable is an essential OEM component designed for precise HVAC blower speed adjustment and airflow balancing. As a variable pitch sheave, this part allows technicians to fine-tune the drive ratio by adjusting the distance between the threaded angular discs. When the flanges are moved closer, the belt pitch diameter increases, raising the driven speed; conversely, widening the gap lowers the diameter to reduce fan RPM. This mechanical flexibility is critical for meeting specific static pressure requirements during system commissioning or after retrofitting ductwork. Constructed from high-grade cast iron, this adjustable motor pulley ensures reliable power transmission and maintains proper belt tension in demanding commercial air handlers. For optimal longevity, verify the bore size and ensure the set screws are aligned with the keyway during installation. Using a genuine York replacement pulley guarantees compatibility with existing drive systems, preventing the premature belt wear and vibration often associated with generic alternatives.

• Precision Airflow Tuning: Enables field-adjustable fan speeds to meet exact CFM and air balance specifications without replacing the motor.
• OEM Mechanical Integrity: Manufactured to York’s rigorous standards for balanced rotation and reduced harmonic vibration.
• Enhanced System Efficiency: Optimizes motor amp draw by allowing the blower to operate at the most efficient point of the fan curve.
• Heavy-Duty Construction: Built with durable materials to withstand high-torque start-ups and continuous HVAC operation.

How do I adjust the pitch on the S1-028-12361-700?
To change the speed, loosen the locking set screws and rotate the outer flange. Turning the flange clockwise increases the pitch diameter and fan speed, while counter-clockwise rotation decreases them. Ensure all set screws are tightened onto the flat portion of the threads after adjustment.

Can I replace a variable pulley with a fixed sheave?
Yes, technicians often replace variable pitch sheaves with fixed pulleys once the final system balance is established. This can reduce long-term belt wear, provided you accurately calculate the final pitch diameter used during balancing.

What causes belt squealing on a variable pulley?
Squealing typically indicates improper belt tension or misalignment between the variable driver and the fixed driven sheave. Because variable pulleys change width as they adjust, always re-check laser alignment after any pitch modification.

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.