366 / 416
9
N-12
© FANTECH
2016
INSTALLATION, WIRING DIAGRAMS & FAN TROUBLE SHOOTING
Axial Flow (Cont.)
Problem
Possible Cause
Recommended Action
3.5 Disintegrated Impeller
Possibly caused by the blades being
struck by loose material in the duct
system.
Ensure the ducts are clear of all debris.
Replace the impeller.
Excessive impeller speed.
Check the motor speed and, if belt-
driven, the pulley ratios. Replace the
impeller.
4.0 BELT-DRIVES
Problem
Possible Cause
Recommended Action
4.1 Various problems
The belts are loose and striking the belt-
guard.
Adjust the belts to the correct tension.
Belts are wearing out too quickly and/or
the belts are too tight.
Adjust the belts to the correct tension.
Also check the belts are a matched set, if
they are not replace the complete set.
The pulleys are worn.
Replace both the pulleys and belts.
The belt may be the wrong cross-section
for the pulley.
Check and replace the belts as
necessary.
The pulleys may be incorrectly aligned.
Check the pulleys and realign as
necessary.
The drive selection may be incorrect.
Check and change as necessary.
The fan, motor or its base may not be
securely fastened.
Check and secure as necessary.
5.0 ELECTRICAL
Problem
Possible Cause
Recommended Action
5.1 Fan running the wrong way.
Incorrect wiring.
To reverse the rotation of a three-phase
motor interchange any two supply leads.
To reverse the rotation of a single-phase
motor interchange leads on the start
winding. Refer to the directions in the
motor junction box.
This note applies to single-speed motors
only. For 2-speed motors refer to the
supplier.
5.2 Fan won't run
Wrong electrical supply.
Check the electrical supply matches the
motor nameplate.
Electrical connections in the motor
terminal box or starter are not tight.
Check and tighten as necessary.
For single-phase motors the capacitor is
not wired in or is faulty.
If a capacitor is fitted check with a
multimeter or replace.
Fuses are blown
Before replacing fuses check the motor
circuit for any faults.
Belts on belt-driven units have broken.
Replace the belts and re-align the drive.
Overloads have tripped out.
Check the motor before resetting the
overloads.
If a variable speed drive (VSD) has been
fitted incorrect installation can cause an
electrical 'spike' causing the motor
windings to fail.
Check the motor windings and if failed
replace the motor. Check the installation
is in accordance with the VSD supplier's
recommendations.
5.3 Fan runs in alternate direction.
The capacitor is not in circuit or it could
be faulty.
Check with multimeter or replace.
Alternatively, the connections could be
poor or incorrect.
Check all connections and ensure there
are no loose terminals.
FAN TROUBLE SHOOTING
N