Impeller Type Ge And Le; Impeller Type Lt; Assembly Of Motor, Impeller With Casing; Installation And Fitting Of The Fan - Helios AVD Series Montage- Und Betriebsvorschrift

Axial-flow Fans AVD.., AVD.. Ex

2.4.4 IMPELLER TYPE GE AND LE

Assembly:
The shaft hub is screwed to the welded and galvani-
zed impeller hub, which is made of sheet steel. The
impeller blades are fastened at the root of the impel-
ler blade with a two-piece clamping ring to the sup-
port of the impeller hub. The clamping ring halves are
equipped with a graduation from 0° to 30°, suitable
for the adjustment of the impeller blades.
The pitch angle set on the graduation of the clamping
ring corresponds to the angle at the outer profile (no-
minal diameter). The clamping rings for the reinforced
execution of the impeller are turned or for the regular
execution formed from sheet metal. If the impeller is
reinforced, the blade root is provided with a journal.
Additionally the journal is locked with a shear pin.
(see pic. 8)
pic. 8
Shaft hub
Impeller in regular Impeller in reinforced
execution
Two piece
Blade root
clamping ring
with journal
Shear pin
Installation of impeller:
The installation position is seen in pic. 9
pic. 9
NS
Direction of rotation
ND
Direction of rotation
.
In case of dismantled delivery the impeller blades
must be installed in the correct position of the impel-
ler hub according to the numbering system, as in 2.4
described. After inserting an impeller blade the blade
root in reinforced execution must be locked with a
shear pin. Now the impeller blades can be screwed
to the impeller hub by means of the clamping rings
as well as the screws and nuts. Before the screws
and nuts are tightened with the specified torque the
pitch angle of the impeller blade mentioned in the or-
der confirmation must be adjusted by means of the
graduation on the clamping ring. Tightening mo-
ments are as follows:
M6 M8
19 Nm 42 Nm
Data for screws and nuts for grade 10.9
Other pitch angles require a release by Helios.
NOTE! We recommend after an adjustment of the
pitch angle a balancing of the impeller again

2.4.5 IMPELLER TYPE LT

Assembly:
The impeller type LT is manufactured only as a com-
plete impeller with non-adjustable impeller blades. Af-
ter the layout the pitch angle is determined and the
impeller blades with the impeller hub are match-dril-
led and locked ex factory. The impeller can be produ-
ced in execution ND or NS. Impeller in execution NS
is shown in pic.10:
execution
pic. 10
Air flow direction
Impeller
blade
The installation of the impeller is carried out via fa-
stening parts, screw, lock washer and sheave. The
water protection cover in the centre of impeller hub
must be removed first and be installed after installati-
on of the impeller again.
3. 3. ASSEMBLY OF MOTOR, IMPELLER WITH
CASING
If the fan is delivered in separate assembly groups li-
ke motor, impeller and casing these assembly groups
must be mounted. First the motor flange and the
bearing surface at the casing are to be cleaned from
dirt particles. Now, the motor must be fixed to the fit
in the casing vertically to the bearing surface and
then be tightened with the specified tightening mo-
ments.
With larger fans standing on mounting feet gear mo-
tors are used in foot-mounted execution. In case of
dismounted delivery these must be mounted accor-
ding to the fan description.
If the impeller is installed, as described in the installa-
tion and operation instruction, the assembly with the
drive and the casing can be carried out.
Suitable screws, locking devices, washers are to be
used. Now the gap between the casing and blade tip
must be checked (see chapter 1.4.).

4. INSTALLATION AND FITTING OF THE FAN

The building and the ventilation system respectively
must be examined before installation of the fan for
sufficiently stable and rigid statics. A safe mounting
and bracing of the fan is to be guaranteed. Specially
trained personnel may only carry out the installation
and the mounting of the fan. When installing observe
the valid regulations for labour protection and acci-
dent prevention. Any contact with rotating parts must
be avoided. Make sure that no materials, which could
M10 M12 M14 M16
85 Nm 130 Nm 230 Nm 330 Nm
Direction of rotation
Water protection cover
Impeller blade
match-drilled and locked
13
be sucked in, are close to the suction area of the fan.
Certain fans are delivered serially with a protection
grille. The protection against accidental contact is to
be examined and guaranteed however generally by
others (see EN 294). Depending on the installation
conditions diverse safety grilles can be delivered as
accessories. Fans protected by their installation in
ventilation channels or closed aggregates do not
need a protection grille, if the installation guarantees
the same protection (see DIN 31001 and 24167). We
emphasize that the installer will be held responsible
for accidents occurring as a result of missing protec-
tion devices. The regulations of the protection against
accidental contact must be adhered to also in case
of an impeller delivery.
When installing heed to obviate body sound trans-
mission, e.g. by using flexible connectors when in-
stalling in ducts (see accessories). When installing in
concrete and lightweight constructed walls and
wood panels avoid tightening the fixing screws too
tightly. To prevent loosening secure screws accor-
dingly.
ATTENTION!
With fans which cause a tilting moment due to
the installation position and centre of gravity the
accessories like flexible connectors, anti vibrati-
on mounts, extension duct, bell mouth, mounting
feet must be selected properly and installed cor-
rectly (see pic. 11).
pic. 11
wrong assembled accessories
right
assembled accessories
If accessories are installed incorrectly they can be da-
maged due to the wrong installation. For damages
due to a wrong assembly of the accessories all war-
ranty claims against Helios are excluded. For critical
installation situations please contact Helios.
The fan performance can only be achieved if unhin-
dered suction and discharge is provided. Therefore it
must be considered the following:
- For unhindered suction and/or discharge the free
space area to the fan (suction side and/or pressure
side) should be at least 1,5 times the fan diameter
in length.
- On the suction side an inlet cone (bell mouth)
should be installed.
- A correctly laid out discharge diffuser can help to
save energy
- With fans which are installed in duct adapted and
required radii and/or distances from connecting