Roof Supply Fan
7
®
Maintenance
To preserve the reliability and performance designed
into the fan, regularly scheduled maintenance should be
performed. Items to be checked at each maintenance
interval are filters, belts, bearings, fasteners, lubrication
and removal of dust and dirt.
Filters
One-inch washable aluminum mesh filters are standard
on both models. Optional two-inch filters may be
supplied on some fans. Filters should be cleaned on a
regular basis for optimum efficiency.
To remove the filters, first remove the fan cover by
releasing the four latches. Place the cover in an area
where wind will not blow it off the roof. The filters can
be lifted out and washed in a mild detergent solution.
If desired, an adhesive spray available at most filter
distributors can be applied to increase filter efficiency.
Belts
Belt tension should be checked two times during the
first 24 hours of operation and during each scheduled
maintenance thereafter. Premature belt failures are
frequently caused by improper belt tension, either too
tight or loose. The proper belt tension for operating a
V-belt is the lowest tension at which the belt will not
slip at peak load conditions. For initial tensioning, belt
deflection should be 1/64 inch for each inch of belt
span, determined by
using moderate thumb
pressure half way
between pulley centers.
For example, the belt
deflection should be 1/2
inch if the belt span is
32 inches, see Figure 4.
Belt tension can be adjusted by loosening the motor
plate hinge bolts and adjusting the jack screws as
required. All units are supplied with either a painted
steel motor bracket or a galvanized motor plate for
larger motor frames. To adjust belt tension on units
equipped with the painted steel motor bracket, simply
adjust the single jack screw.
For units equipped with a galvanized motor plate, both
jack screws must be adjusted equally. Check pulley and
belt alignment after adjusting belt tension; Figure 2.
DANGER
Disconnect and secure to the “off” position all
electrical power to the fan prior to inspection or
servicing. Failure to comply with this safety precaution
could result in serious injury or death.
DANGER
Pour écarter les risques de blessure grave ou de mort,
débrancher et verrouiller l’alimentation électrique en
position « Arrêt » avant tout contrôle ou entretien.
Belt Span
Deflection =
Belt Span
64
Figure 4
Lubrication
Fan bearings on all models are permanently lubricated.
Motor bearings equipped with grease fittings should be
lubricated in accordance with instructions on the motor
nameplate. Motors without grease fittings are lubricated
for life.
Cleaning
Motors and fan wheels require periodic cleaning to
remove dust and dirt which may accumulate. Motor
cleaning should be limited to the exterior surface only.
Removing dust and dirt from the motor housing assists
in motor cooling and prolongs motor life. Motors should
never be sprayed with steam, water or solvents.
Fan wheels which are left to accumulate dust and dirt
will have poor air performance, loss of efficiency and
possible damaging vibration due to an unbalanced
condition.
Periodic cleaning is a good investment in preserving the
reliability and performance designed into the fan.
