Greenheck Downblast Centrifugal Roof Exhaust GB-540

Check belts for wear and tightness.

Verify belt type matches the original unit specifications.

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.

Adjust belt tension after the first 24-48 hours of operation

Adjust and tighten belt 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.

Are grease fittings provided on the motor?

Replace grease in motors where temperatures do not exceed 104ºF (40ºC) after 2,000 hours of running time.

Ensure the following are checked after maintenance

Ensure safety precautions are in place around moving parts

Verify that the grease gun is set to a maximum of 40 psi

Check the condition of the bearings

Rotate bearings during lubrication if safe to do so

Enter the number of lubricant shots used (1 or 2 recommended)

Was a high grade lithium base grease used?

Did a slight bead form around the seal?