5
6.5 Motors
The motors have greased-for-life bear-
ings, which are to be replaced according
to the manufacturer’s instructions.
6.6 Dismounting of motors
Before beginning work on motors, fol-
low the procedure in section “6.2 Precau-
tions before maintenance”.
References to specific items below are to
figure 9, unless noted otherwise.
Dismounting motors
1 Disconnect the supply cable from the
switch (figure 1, item 06).
2
AUO/ARO/ARP/AUZ/AUT/ART:
Support the fan, remove the nuts from
the four expansion bolts item 01 and
take down the fan.
AZT:
Support the fan and remove the
fasteners item 01 and take down the
fan.
3
AUO/ARO:
Remove set screws item
02 and dismount silencers items 03.
Mark the silencers with tape so they
are not mixed up.
ARP/AUZ:
Remove set screws item
02 and dismount the silencers and
suspension brackets. Mark positions
of brackets and silencers with tape so
they are not mixed up.
AUT/ART:
Loosen and remove the
wire guards in both ends (figure 1,
item 11).
AZT:
Loosen the two pairs of nuts and
bolts, which hold the hose clamp
together. Remove clamp and outlet
cone. Also, remove the wire guard on
the inlet.
4 Disconnect the cable from terminal
box to motor.
5
AUO/AUT/ART/AUZ/AZT:
Remove
hub cap item 06 by removing screws
item 04, and centre disc item 05. For
AUZ and AZT, also remove the centre
bolt item 13.
ARO/ARP:
Remove the rivets in the
guide vane arrangement item 11 to
remove the arrangement.
6 Dismount rotor item 07 by means of a
puller fastened in two threaded holes
of hub boss (M8 × 16 with distance
50 mm).
7
AUO/ARO/ARP/AUT/ART:
Remove
the four set screws item 08.
AUZ and AZT:
Remove the nuts and
bolts, items 14 and 15.
8 Mark the motor position and
direction of rotation for later
remounting.
9 Dismount motor, item 10.
AUO/ARO/ARP/AUT/ART:
Remove
the motor mounting flange item 09.
AZT:
Remove the four stiffeners items
16 that hold the motor.
Service the motor according to the
manufacturer’s instructions. These are
included with the fan.
6.7 Mounting of motor
Assemble the fan, after motor service.
See section “6.6 Dismounting of motors”
and perform the steps in reverse order.
References to specific items below are to
figure 9, unless noted otherwise.
Mounting motor
1 Mount motor, item 10.
AUO/ARO/ARP/AUT/ART:
Remount the motor with the set
screws, item 08.
AUZ and AZT:
Remount the motor
with bolts and washers, items 14 and
15. For AZT also mount the stiffeners,
items 16.
2
AUO/ARO/ARP/AUT/ART:
Check
that the mounting flange item 09 is
correctly located and that the motor
shaft is centred in the fan casing,
before tightening the set screws item
08.
AUZ and AZT:
Check that the motor
shaft is centred in the fan casing,
before tightening the bolts items 14.
3 Mount the rotor item 07 on the motor
shaft by means of a jack fastened in
the threaded hole of the motor shaft.
Press the rotor hub to contact against
the motor shaft collar.
Important:
Do NOT use hammers or
similar, as the motor
bearings are sensitive to
shocks.
Check that the blade tip clearance is
the same throughout the
circumference. Adjust the motor
position in the suspension
arrangement if needed.
4 Connect the cable between motor and
terminal box. Use same routing as
from the factory.
5
AUO/AUT/ART:
Mount hub cap item
06, centre screw item 04 and centre
disc item 05 and tighten.
AUZ and AZT:
Mount the centre disc
item 05, centre bolt item 13, hub cap
item 06 and screws items 04 and
tighten.
6
ARO/ARP:
Mount guide vane
arrangement item 11 by means of ten
blind rivets ø3.2 × 10 (monel metal).
ARO 500:
Use ten blind rivets ø4 × 10
(monel metal).
7
AUO/ARO:
Mount silencers items 03
to fan casing by means of set screws
item 02.
ARP/AUZ:
Mount silencers items 03
together with the suspension brackets
to the fan casing by means of set
screws item 02.
AUT/ART:
Mount wire guards
(figure 1, item 11).
AZT:
Mount the outlet cone, fit the
hose clamp and tighten both pairs of
nuts and bolts to hold the cone.
Mount the wire guard on the inlet.
8 Lift the fan back into position.
AUO/ARO/ARP/AUT/ART/AUZ:
Mount four expansion bolts item 01,
nuts and tighten.
AZT:
Mount fasteners through the fan
top plate and the ceiling mounted
base plate. Adjust the outlet cone for
correct directional thrust. Tighten
nuts and bolts on the hose clamp to
secure the cone.
9 Connect the supply cable to the
terminals (figure 1, item 06).
To start the fan, follow the procedure
described in section 6.
6.8 Blade pitch adjustment
The blade pitch has been adjusted in the
factory with a mounting fixture to deliv-
er the performance required. Do not
change the blade pitch without previous
agreement with Novenco.
6.9 Troubleshooting
In case of breakdowns, the following
checklists should be completed, before
calling for service.
Lacking performance
• Inlet or outlet blocked
• Auxiliary fans stopped
• Motor defective
• Motor disconnected
• Electric connection defective
• Wrong direction of rotation
Noise and vibrations
• Motor bearings defective
• Rotor in imbalance
• Rotor worn or damaged
• Loose components
• Rotor blades with different pitch an-
gles (loose blades).
• Fan operates in the stalling area which
may result in breakdown. Correct er-
rors – see “Lacking performance”.
Important:
Grease all bolts and screws
before mounting.
