A direct-replacement blower motor engineered to restore proper airflow in HVAC, ventilation, and air-handling equipment. The Dayton 1TDR9 (also sold as NBK part 20520) replaces aging or failed Dayton 4C264 and 4C448 units with a ball-bearing-equipped, Class B insulated motor rated for continuous duty at up to 104 deg F inlet air temperature.
When a blower motor fails, the fastest path back to operation is a confirmed drop-in replacement with matching airflow, voltage, and mounting dimensions. The 1TDR9 matches the performance spec of its predecessors -- 463 CFM at 1520 RPM on 115V/60Hz -- so your system delivers the same static-pressure performance it was designed for, without recalibration or ductwork changes.
The motor runs counter-clockwise rotation (viewed from the inlet side), which is the standard orientation for the blower assemblies these units are designed to serve. Verify rotation direction before ordering if you are not replacing a 4C264 or 4C448 directly.
Ball bearings instead of sleeve bearings extend service life, handle higher operating temperatures, and tolerate non-horizontal mounting orientations.
Built-in thermal overload protector shuts the motor down if it overheats and resets automatically, protecting windings from burnout.
Class B winding insulation is rated to 130 deg C, providing a meaningful safety margin over the 104 deg F (40 deg C) max inlet air temperature rating.
Overall housing dimensions of 9-1/8 in W x 9-3/8 in H x 8-1/2 in D fit the same equipment footprint as the 4C264 and 4C448 without modification.
At 463 CFM free-air delivery and 1520 RPM, this motor is suited to residential and light-commercial ventilation, HVAC air-handling units, and industrial blower assemblies where the original Dayton blower package was specified. The 5-1/8 in diameter blower wheel (not included -- see "What's in the Box" below) pairs with the 12 mm shaft diameter of this motor.
Rotation is counter-clockwise when viewed from the shaft/wheel end. The shaft diameter is 12 mm. Always confirm your existing motor's rotation direction and shaft size before installation -- a motor with incorrect rotation will move air in the wrong direction and may not fit the blower wheel assembly.
This is a motor-only replacement. The blower wheel, housing, and any mounting hardware from the original installation are reused. Standard installation steps: