Howden 24-07.030r04 16/25
E-series Axial Flow Cooling Fans
Balancing
The impellers are balanced according to ISO
1940, balancing quality grade G6,3.
Impellers with a diameter smaller than 4455
mm or 14 feet are balanced in assembly ac-
cording to a certain hub-plate configuration:
A. Clamping pieces installed at flow inlet side
B. Clamping pieces installed at flow outlet side
A sticker on the hub-plate marks the applied
balancing method. See figure 18.
Figure 18 Sticker as attached on the hub-plate
If not agreed otherwise, the impeller is bal-
anced according method B by default.
IV. COMMISSIONING
a. Check all bolts and nuts for proper tighten-
ing (including the fan casing hardware).
b. Make sure that the metal bearing support
structure is electrically earthed in order to
avoid sparkling by electrical static dis-
charge.
c. Turn the impeller by hand to check that it
runs freely and does not rub or strike the
impeller housing.
d. Impellers driven by a two-speed e-motor:
Only switch from “high speed” to “low
speed” after the impeller speed has
slowed down to less than the “low speed”.
To be sure you may choose to switch the
e-motor only after the impeller has come
to a complete standstill. Neglecting this
rule may lead to irreparable impeller
damage!
e. Make sure that all tools and assembly aids
like beams, supports, ladders…etc. have
been removed. All the required protec-
tions, mechanical and electrical must be
installed before starting the fan. Make sure
that all applicable local safety require-
ments have been met to ensure safe op-
erating conditions.
f. „Bump” the motor to check for clockwise
rotation of the impeller, when viewed into
the air stream (also see figure 6).
Important
If the impeller is installed in a different hub-
plate configuration than it was balanced,
e.g. configuration B for an installation with
the clamping pieces at flow inlet side, you
run the risk of an unquiet operation.
To Next Page
Loading...
