The Dayton 1TDT4 is a direct replacement blower motor designed to restore proper airflow in HVAC, furnace, and ventilation systems. It replaces the discontinued Dayton 2C946 and is also catalogued as NBK Parts 20519. With an 805 CFM rating, ball bearing construction, and automatic overload protection, this unit is built for reliable, continuous-duty service.
If your system originally used a Dayton 2C946 blower motor, the 1TDT4 is the correct replacement part. This motor matches the original mounting footprint, shaft configuration, and performance specs, making swaps straightforward for experienced HVAC technicians and capable DIYers alike.
The dual-speed design (910 RPM low / 1030 RPM high) allows for staged airflow control -- useful in systems that run a lower blower speed for heating and a higher speed for cooling or air circulation. At 115V and 50/60 Hz compatibility, it works with standard North American electrical systems.
Delivers strong, consistent airflow for medium-to-large HVAC and ventilation applications requiring high-volume air movement.
910 RPM low speed and 1030 RPM high speed give the connected system two-stage airflow control without additional hardware.
Ball bearings provide longer service life, reduced friction, and better performance under continuous-duty cycles compared to sleeve bearing designs.
Built-in thermal overload protection shuts the motor down if it overheats, preventing burnout and protecting the connected system.
Class B insulation rating means the motor windings are rated to handle sustained temperatures up to 130 deg C (266 deg F), well above the 104 deg F maximum inlet air temperature for this unit. This thermal headroom contributes to long service life even in demanding environments.
The clockwise rotation of the blower wheel is fixed -- confirm your system requires clockwise rotation before ordering. Swapping rotation direction on a centrifugal blower requires a different motor or wheel orientation and cannot be field-reversed on this unit.
Dual-speed motors like the 1TDT4 typically use a multi-lead wiring configuration. The low-speed winding draws 2.60A and the high-speed winding draws 2.80A at 115V. Refer to the lead color coding on the motor tag for correct speed-tap connections. If you are replacing a 2C946, the wiring connections should be identical.
This motor operates on both 50 Hz and 60 Hz power supplies at 115V. Performance specs (CFM, RPM) are rated at 60 Hz, which is standard in North America. On 50 Hz systems, expect slightly lower RPM and airflow output.
This motor rotates clockwise (when viewed from the shaft end). Installing a motor with incorrect rotation on a centrifugal blower wheel will significantly reduce airflow and can damage the wheel. Verify rotation direction on your existing unit before purchase.