Greenheck Downblast Centrifugal Roof Exhaust GB-160

Check belts for wear and tightness.

Verify belt type matches the original unit specification.

Loosen the tensioning device to allow removal of the belt by hand.

Adjust belts as shown in 'Pre‑Starting Checks.'

Check pulley setscrews for tightness.

Inspect bolts, setscrews, and motor mounting bolts

Adjust and tighten as necessary

Loosen the setscrew holding the bushing and shaft key in place, if present.

Loosen and remove the socket head cap screws fastening the bushing to the hub.

Select the mounting type for socket head cap screws installation

Tighten the socket head cap screws an eighth of a turn at a time, alternating between them until the hub comes loose from the bushing.

Clean all surfaces of hub and bushing to remove any oil or residue.

Select the mounting style for bushing installation

Use the keyway setscrew to hold the shaft key and bushing in place, if present, without overtightening.

Disconnect all electrical power to the fan and secure to the 'off' position.

Ensure the unit is made non-functional by removing fuses and locking off the disconnect.

Inspect the wheel and housing for oil and dust accumulation.

Is there any oil or dust accumulation on the wheel or housing?

Clean the wheel and housing evenly to prevent imbalance and vibration.

Is the wheel and housing clean and free of oil and dust?

Fasteners and Setscrews Inspection

Check all fasteners and setscrews for tightness

Does the wheel rotate freely and is it aligned as shown in Figure 7?

Was the wheel position verified for movement during shipment?

If necessary, was the wheel realigned?

If G model, was the centering height alignment adjusted by loosening the set screws and moving the wheel?