Howden ELF - Trouble Shooting

Howden 24-07.030r04 20/25
E-series Axial Flow Cooling Fans
Service Manual
VII. TROUBLE SHOOTING
In case of any failure, please contact Howden stating the impeller order number as mentioned on
the nameplate located at the hub of the impeller.
Problem
Possible cause
Possible solution
Air volume low.
Fouling of system.
Clean system air-cooler
bundles or cooling tower
fill.
Obstacles in housing/air
stream.
Check actual total area of
obstacles and impeller
housing inlet shape
against original selection.
In dry-coolers the mini-
mum required free height
of the air inlet area is 1.0
times the fan diameter.
This shall be higher in
case of multiple row units.
Static pressure higher than
specified.
Increase blade angle.
(Up to 3 degrees, thereaf-
ter do selection check).
Blade angle decreased
due to rotation of the
blades. (I.e. forgot to re-
torque the U-bolt nuts).
Re-set blade angle and
refer to the blade installa-
tion instructions for the
correct torque.
Air temperature higher
than design air tempera-
ture.
Increase blade angle.
(Up to 3 degrees, thereaf-
ter do selection check).
Power absorption (too)
high. (1)
Fouling of system.
Clean system air-cooler
bundles or cooling tower
fill.
Obstacles in housing/air
stream.
Check actual total area of
obstacles and impeller
housing inlet shape
against original selection.
In dry-coolers the mini-
mum required free height
of the air inlet area is 1.0
times the fan diameter.
This shall be higher in
case of multiple row units.