The Dayton 1TDU7 is a direct replacement blower motor delivering 127 cubic feet per minute at 3235 RPM on a standard 115V/60Hz circuit. It replaces the discontinued Dayton 4C825 and is also cataloged as NBK Parts 20532. Ball bearing construction, automatic overload protection, and a compact housing make this a reliable drop-in for HVAC equipment, furnace blowers, and ventilation systems where the original motor has worn out.
When a blower motor fails, getting the right replacement quickly matters. The 1TDU7 matches the electrical and physical profile of the Dayton 4C825, so you can restore airflow without fabricating new mounts or rewiring. At 0.32 amps draw on 115V, this motor is highly efficient for its output class, and the Class B insulation rating keeps it stable in continuous-duty applications.
Ball bearings -- rather than sleeve bearings -- extend service life and allow the motor to be mounted in multiple orientations without lubrication concerns. The integrated automatic overload protector shuts the motor down before thermal damage occurs and resets automatically once the unit cools.
Longer service life than sleeve-bearing motors. Supports multiple mounting orientations and resists wear under continuous operation.
Built-in thermal overload protector prevents burnout. Resets automatically after cool-down -- no manual reset required.
Overall dimensions of 14-5/8 in W x 3-7/8 in H x 3-5/8 in D allow installation in tight equipment cabinets where space is limited.
Only 0.32A at 115V -- approximately 37 watts -- making this motor easy on circuits and compatible with most residential and RV 15A/20A branch circuits.
The 1TDU7 is the current catalog replacement for the Dayton 4C825 blower motor. It is also sold under the NBK Parts number 20532. If your existing unit carries either of those part numbers on its label, the 1TDU7 is the correct replacement. Always verify the flange bolt pattern and shaft diameter (12 mm) against your application before ordering.
Class B insulation is rated for continuous duty up to 130 deg C winding temperature (with a 40 deg C ambient baseline). The maximum inlet air temperature for this motor is 104 deg F (40 deg C). Do not use in applications where incoming air regularly exceeds that temperature, such as direct exhaust recirculation.
The 1TDU7 uses a standard single-phase, 115V/60Hz power connection. Disconnect power before servicing. Match the rotation direction of the original motor before wiring -- blower wheels are directional and will not move rated airflow if the motor runs backwards. Confirm wheel-to-housing clearance after installing the blower wheel on the 12 mm shaft.