Service access – Greenheck RDU/RBU/RBUMO (455700) User Manual

Page 5

Propeller Upblast Roof Fans

Service Access

Model RBUMO - Motor Out of Airstream

Model RBUMO simpliﬁes inspection and servicing with
the “motor out of the airstream” design. A removable
motor cover enables quick and easy access to the
motor, belt, and drives for replacement or adjustment
from the roof deck.

Butterfly
Damper
Blades

Lubrication

Refer to the paragraph on bearings for bearing
lubrication. Many fractional horsepower motors installed
on the smaller fans are lubricated for life and require
no further attention. Motors equipped with oil holes
should be oiled in accordance with the manufacturer’s
instructions printed on the motor. Use a high grade SAE
20 machine oil and use caution not to over lubricate.
Motors supplied with grease ﬁttings should be greased
according to directions printed on the motor.

Removal of Dust and Dirt

Dirt clogs cooling openings on the motor housing,
contaminates bearing lubricant, and collects on
propeller blades causing severe imbalance if left
unchecked. The exterior surface of the motor, fan panel
and entire propeller should be thoroughly cleaned
periodically. Use caution and do not allow water or
solvents to enter the motor or bearings. Under no
circumstances should motors or bearings be sprayed
with steam or water.

Damper Inspection and Service

IMPORTANT: Butterﬂy dampers on units supplied
with optional spring lifter bars are under spring
tension and will open forcefully if the fusible link is
released. Butterﬂy dampers should be inspected
for proper operation at each service interval.
Check for freedom of movement and general
condition of the damper blades and hinge rods.

Option B

Remove bolts (8) that
fasten the lifting lugs.
This will allow the
outer windband to be
removed. Next, the
damper assembly will
need to be removed.

Option A

Remove bolts (8)
that fasten the entire
windband/damper
assembly to the fan.

Removable Windband

The windband can be removed by removing the bolts
from the four windband mounting brackets. With the
windband removed, access to the fan can be gained
through the butterﬂy dampers. This service feature
applies to models RBU, RBUMO and RDU.

Removable
Motor Cover

Removable
Windband

Servicing of propeller and bearings can also be
accomplished by removing the fan panel/windband
assembly from the fan base.

IMPORTANT

To service the fan it is recommended the fan be
accessed from below (looking up). If this is not
possible, or the fan is equipped with inlet guards,
the fan may be serviced from above by taking off the
removable windband.

For fans equipped with damper lifters

refer to warning on Page 3.

Models RBU & RDU - Motor In Airstream

To service motor, grease bearings, adjust tension and
replace belts, models RBU and RDU motors and drives
can be accessed from below the fan. If the fan was
ordered with an inlet guard, all service will need to be
completed from above the fan.

Follow the instructions for:

• Removable

Windband

• Prop

Removal

• Adjust Tension - Remove Motor