365 / 416
N-11
© FANTECH
2016
INSTALLATION, WIRING DIAGRAMS & FAN TROUBLE SHOOTING
FAN TROUBLE SHOOTING
N
2.0 MECHANICAL (Cont.)
Problem
Possible Cause
Recommended Action
2.6 Vibration (Cont.)
Vibration being transmitted through the
building structure.
Check vibration isolators have been fitted
and, if fitted, check they are correctly
positioned.
Vibration isolators are fitted but not
strong enough. If bottoming, adjust if
possible or replace with more suitable
mounts.
Fit flexible connectors between the fan
and ductwork.
3.0 IMPELLERS
NOTE: If there is any doubt about the impeller contact the supplier, do not run the fan.
Refer to Do’s and Don’ts section of this catalogue for design advice.
Centrifugal
Problem
Possible Cause
Recommended Action
3.1 Impeller excessively noisy
The impeller may be striking the fan
casing or inlet cone, check for the
following causes:-
Impeller may be loose on the motor or
drive shaft.
Tighten the fixings.
Impeller incorrectly mounted onto the
shaft
Re-install the impeller onto the shaft with
the key installed correctly
Impeller not centred in the casing
Adjust to the correct position.
Casing inlet cone may be damaged
Repair the damage.
Bent motor or drive shaft
Replace the shaft
Impeller not centred on the inlet cone.
Check and re-align as required.
The inlet cone has been damaged
Repair or replace.
Shaft loose in bearings.
Tighten the bearing rings.
Bearing loose on its support.
Tighten the fixing bolts.
The cut-off in the fan discharge has been
damaged.
Repair or replace.
Cut-off is insecure.
Refit securely.
3.2 Damaged Impeller
Impeller bulging. This could be caused
by the impeller being built from lighter
than specified materials or the fan is
running above its recommended speed.
Replace the impeller but also check the
fan speed. Advise supplier of the
problem.
Axial Flow
Problem
Possible Cause
Recommended Action
3.3 Impeller excessively noisy
Impeller blades may be loose and could
be striking the fan casing.
Contact the supplier.
The motor may have moved.
Check the alignment of the motor, relative
to the casing, and tighten the fixing bolts.
Contact the supplier.
The blade tip clearance may be
insufficient.
Trim the blades to suit, check with the
supplier for advice.
3.4 Bent blades
The blades may have been damaged
during transit or by loose material in the
duct system.
Check the condition of the fan and
impeller on receipt and for debris in the
duct. Replace the impeller if damaged.
Bent blades can be caused by the fan
running in stall or the air entry/discharge
conditions to the fan creating excessive
vibration.
Check the air entry conditions to the
impeller do not generate excessive
turbulence.
Replace the impeller.