3
fan, anti-vibration mountings may be
inserted between fan and support and
flexible connections fitted in the ducts after
the fan. Anti-vibration mountings and
flexible connections are optional extras.
Secure anti-vibration mountings (fig. 4,
item 10) in the ends of the c-profile by
means of bolts (item 11).
Mount base plates (item 12) for attachment
in the foundation/floor at the bottom of the
rubber element.
The natural frequency of the support must
differ at least 20% from the fan speed.
If the motor is provided with drain holes
for condensed water the fan must be
oriented so that the holes are at the lowest
point and point downwards.
It is of the utmost importance for the
performance and sound level of the fan that
the airflow is unimpeded and free from
eddies.
4.4 Duct connection
A downstream guide vane arrangement
with core can be mounted on the NovAx
axial flow fan with which the fan can obtain
a very high efficiency and be used for
connection to duct.
The duct on the fan outlet side must be
designed to ensure smooth and
undisturbed flow of the air. Avoid sharp
duct bends immediately after the fan.
ACP and ACG fans are prepared for
circular duct connections on the outlet side.
Flanges supplied as standard comply with
Eurovent 1/2.
Systems with a higher vibration level or
more exacting performance requirements
must be provided with expansion joints
between fan and duct. The fan must not be
used as support for ducts.
It is important to allow for free areas to
facilitate mounting and dismounting as
well as ordinary maintenance.
4.5 Electric connection
Fans fitted with drives must be installed in
accordance with the EU standard for
electromagnetic compatibility (EMC). The
shielding and connection to ground
eliminate interference and protect the
motor bearings and windings. Refer to the
motor documentation for methods to avoid
impairment of the mains power quality.
Prescribed methods may involve
installation of a rectifier, filters etc.
Connection to the mains is done directly in
the motor terminal box.
Connect the motor cables according to the
connection diagram on the inside of the
box lid. Refer also to the motor name plate
as well as the order specification.
Check the fan rotation direction once the
motor is connected. Do this by briefly
flicking the fan power on and off. It must
comply with the arrow on the fan casing. If
the direction is wrong, disconnect the main
power supply and check the connections.
Reversible fans must be fitted with time
delays to allow the impeller to become
stationary, before changing direction.
Running the fans in reverse increases the
risk of stall and shortens fan life.
5. Start of operation
5.1 Prior to start of operation
Prior to start of operation check that the fan
and duct connections are clean and free
from tools and foreign substances.
Also ensure that the electric connections
meet the prescribed requirements, that any
wire guard fitted on the fan inlet or outlet
side is correctly mounted and that the
direction of rotation of the fan complies
with the arrow-plate (check by short-time
operation).
See fig. 6, items 01 and 02.
5.2 Motors with Y/
Δ
-start
The relay must be set to the calculated time.
5.3 Start-up procedure
• Start the fan.
• Check that no abnormal noises occur.
• See that the vibration level is normal.
The vibration level at the fan
operating speed must not exceed 7
mm/s, rms*, measured radially at
two points, 90° offset and at the free
shaft end of the motor. Otherwise, the
fan must be balanced.
Operation at a vibration level exceeding 11
mm/s, rms*, is not allowed in case of fixed
fan position.
Operation at a vibration level exceeding 18
Figure 5.
Mounting foot for types ACP
and ACG 1250-1600 (optional)
Important:
The installation and
connection to the supply
network must be done by
authorised personnel and
be in accordance with
current legislation.
Important:
Only fans with steel hubs
may be run in reverse.
Reversible operation
increases risk of fan stalling.
If the fan stalls, the service
life is shortened.
Figure 6.
NovAx Type ACG
Figure 7.
Dismounting/mounting of types ACG and ACP
1. Motor
2. Motor flange
3. Wire guard
4. Motor shell
5. S-washer
6. Set screw
7. Impeller
8. Centre disc
9. Centre screw
10. Set screw
11. Washer
12. Hub
13. Outlet guide vanes
14. Nut
