3
5. Maintenance
5.1 Cleaning and inspection
The fans should be inspected and
cleaned once a year. In environments
with large dust concentrations short-
er intervals are recommended.
It is important that the impeller be
cleaned as coatings on the blades
may cause imbalance and thus vi-
brations subjecting the bearings to
unnecessary stress. The impeller is
cleaned by dismounting it from the
motor side. See sections “5.4 Dis-
mounting of motor with impeller
from the motor side” and “5.5
Mounting of motor with impeller
from motor side”.
5.2 Dismounting of impeller
from the inlet side
Fig. 4. First, dismount the duct from
the fan inlet side. Then remove duct
connection (pos. 1), inlet cone (pos.
3) and intermediary flange (pos. 5)
by loosening and unscrewing the
nuts (pos. 6). Then remove the screw
(pos. 12) and motor disc (pos. 10)
holding the impeller. Detach the im-
peller using a puller secured in the
two threaded puller holes in the im-
peller hub.
5.3 Mounting of impeller from
the inlet side
Fig. 4. Place the impeller (pos. 9) on
the shaft, mount pos. 10-12, and
tighten the screw (pos. 12). Mount
duct connection (pos. 1), inlet cone
(pos. 3) and intermediary flange
(pos. 5). Remember to check that the
distance between inlet cone (pos. 3)
and impeller (pos. 9) is equally large
everywhere, and that the seal (pos. 8)
still is elastic. Finish by tightening
screws (pos. 6).
5.4 Dismounting of motor with
impeller from the motor
side
Before the fan is dismounted, it must
be ensured that it cannot be started
unintentionally. This is done by se-
curing the service switch with a key.
1. When dismounting the rotor,
first remove the bolts and nuts
attaching the sealing plate and
the motor bracket to the fan
housing. See fig. 5 and 6.
The bolts attaching the motor
bracket to the guide rails should
only be loosened – not removed.
See fig. 7.
Fig. 4
Fig. 5
Fig. 6
