NovAx™
axial flow fan types ACN-ACW ATEX and ACW EX
3
Follow the below guidelines to avoid
resonance.
• Soft suspension:
Fan is fixated
through springs or dampers.
The natural frequency [Hz] of
the system should be at least 20%
below fan speed.
Soft suspensions are available
from Novenco.
• Stiff suspension:
Fan is fastened
to a duct or a stiff wall through
holes in the flanges. The natural
frequency of this system should
be at least 20% above fan speed.
• Elastic structure:
Fan is fastened
to an elastic structure. The
natural system frequency
should be at least 20% higher or
lower than fan speed.
The owner is responsible for
compliance with the above
requirements. Non-compliance affects
the product warranty.
4.2 Installation
Installation of fans
1. Place and orient the fans in
accordance with the airflow direction
arrow on the fan casing.
Position motors with drain
holes with the holes
downwards at the lowest point.
2.
Recommendation:
Install the fans on
support frames. Fans may also be
suspended in the casing flanges or
with special carriers.
3. Check that the rotor rotates freely,
once the fan is mounted in position.
4.
For fans on support frames and with
vibration dampers:
Remove the
transportation rods. These are
marked with a strong colour and are
inserted in the support frame.
4.3 Support frames
These are optional extras and are
recommended for installation.
Support frames must be
grounded to prevent electrical
shocks.
The ACN-ACW ATEX and ACW EX fans
can all be installed on horizontal support
frames or fitted with frames for vertical
mounting. Refer to the order and
technical specifications.
The horizontal support frame consists of
two mounting plates (see figure 2, item
1). Two stiffeners (item 2) are mounted
between the plates with screws M10x20.
Stiffeners are only used from fan size
Ø630 and up.
The vertical support frame for an ACN-
ACW ATEX or ACW EX fan consists of a
plate onto which the fan is mounted in
the flange. Dampers are optional.
To prevent spread of vibrations to the
surroundings, it is recommended to
insert anti-vibration mounts between the
fan and support, and flexible
connections in the ducts before and after
the fan. The connections are available as
optional extras.
Secure anti-vibration mounts (figure 2)
in the support frame by means of bolts.
Mount base plates for attachment to the
foundation at the bottom of the rubber
elements.
The natural frequency of the
support must lie at least 20%
from the fan speed.
The anti-vibration mounts help to ensure
the natural frequency of the system is
below 10 Hz and that the damping is at
least 80%.
4.4 Wire guard installation
Fans must always be installed so that
parts that rotate cannot be touched. The
fans can be optionally fitted with wire
guards on the inlet and outlet sides. If
ducts are connected, these can
alternatively be provided with wire
guards.
Novenco offers wire guards for in-pipe
installation on outlets. Drill holes in the
pipe and fixate with bolts and nuts.
4.5 Connection to duct
The fans must not be used as
structural elements, e.g. for duct
or building support.
Install the fans with optimum conditions
in mind to ensure smooth and
undisturbed airflows. The space before
and after the fans must meet the
minimum requirements in figures 6 and
7. Less space means the fans must be run
at reduced speed.
Allow for free areas to facilitate assembly
and disassembly as well as maintenance.
Flexible connections approved for ATEX
or EX can be placed at least ½D before the
Figure 2.
Horizontal support frame for
ACN-ACW ATEX and ACW EX
Figure 3.
Fans for vertical mounting with
support frame (left) and with
support frame, anti-vibration
dampers and flexible connection
1
2
4
3
Figure 4.
Fan with support frame and anti-
vibration mounts
Figure 5.
In-pipe installation of wire guard
5
6
7
20
Ø400 - Ø560:
Ø630 - Ø1000:
Ø1120 - Ø1600:
6 x Ø7 mm
8 x Ø7 mm
8 x Ø9 mm
Eyebolt
Nut
