How To Replace A Cooling Tower Motor

Replacing a cooling tower motor is a moderate- to heavy-duty HVAC/mechanical task, and must be done carefully because of electrical hazards, heavy components, and work at height.

Below is a safe, high-level overview of how the replacement process is normally done by technicians (not step-by-step mechanical instructions or torque procedures).

Safety Firs

Before any work:

* Lockout/tagout (LOTO) all electrical power

* Verify fan cannot move (wind can rotate it)

* Ensure tower is drained or isolated if needed

* Use fall protection if working on top of the tower

* Use a hoist or team lift—motors are heavy

  High-Level Process to Replace a Cooling Tower Motor

1. Identify the exact motor to match

Cooling tower motors must match:

* HP & voltage

* Speed (RPM / poles)

* Frame size

* Mounting type (Vertical hollow-shaft, solid shaft, or direct-drive)

* Enclosure (TEAO, WPI, WPII)

* Rotation direction

* Shaft length & key type

* Fan/gearbox connection style

This ensures the new motor fits mechanically and runs correctly.

2. Secure the fan and disconnect wiring

Technicians typically:

* Secure or block the fan to prevent rotation

* Disconnect motor wiring in the junction box

* Tag wires for correct reconnection

* Disconnect heater/RTD wiring if present

3. Disconnect the motor from fan or gearbox

Depending on the tower design:

Gear-driven tower (vertical hollow shaft motor)

The motor sits on top of the gearbox with a long vertical shaft.

High-level steps include:

* Remove the belled hub or coupling

* Remove the motor from the gearbox top mounting flange

Direct-drive tower

Fan hub sits directly on the motor shaft.

Technicians:

* Remove fan guard

* Remove fan hub/propeller

* Detach motor from mounting base or frame

4. Lift out the old motor

Motors are usually removed with a hoist, crane, or lifting trolley, never manually.

Cooling tower top decks can be slippery, so secure footing is important.

5. Install the new motor

High-level steps:

* Lower the motor into place

* Align the motor mounting with gearbox or fan hub

* Make sure shaft engagement depth matches OEM spec

* Tighten mounting hardware according to manufacturer guidelines

(Exact torque values and alignment steps vary by brand, and technicians follow OEM documentation.)

6. Reinstall fan, coupling, or hub

Technicians ensure:

* Fan blades are tightened evenly

* Pitch angle is correct

* Fan is centered and balanced

* No rubbing on fan cylinder or shroud

(Improper centering causes vibration.)

7. Reconnect electrical wiring

Reconnect:

* Power leads

* Motor heater leads

* RTDs/temperature sensors (if present)

Confirm:

* Rotation direction matches tower airflow

* Overload settings are correct

* Starter or VFD settings match the motor nameplate

8. Commissioning / Test Run

During startup, technicians check:

* Fan starts smoothly

* Correct rotation

* Vibration level

* Motor current (FLA)

* Noise or rubbing

* Gearbox oil level (if gear-driven)

A brief test is done first, then full load operation.