Greenheck Vane Axial Fans (452954) - Manual (Page 9)

Problem Cause Corrective Action
Motor fails to start
Blown fuses Replace fuses with proper type and rating.
Overload trips Check and reset overload in starter.
Improper power supply
Check to see that power supplied agrees with motor
nameplate and load factor.
Improper line connections Check connections with diagram supplied with motor.
Open circuit in winding or
control switch
Indicated by humming sound when switch is closed.
Check for loose wiring connections. Also verify all control
contacts are closing.
Mechanical failure
Check to see if motor and drive turn freely. Check bearings
and lubrication.
Short circuited stator Indicated by blown fuses. Motor must be rewound.
Poor stator coil connection Remove end bells, locate with test lamp.
Impeller defective Look for broken bars or end rings.
Motor may be overloaded Reduce load.
Motor stalls
One phase may be open Check lines for open phase.
Wrong application Change type or size. Consult manufacturer.
Overload motor Reduce load.
Low motor voltage
See that nameplate voltage is maintained. Check
connection.
Open circuit
Fuses blown, check overload relay, stator and push
buttons.
Motor runs and then
dies down
Power failure
Check for loose connections to line, to fuses, and to
control.
Motor does not come
up to speed
Not applied properly Consult supplier for proper type.
Voltage too low at motor
terminals because of line
drop Use higher voltage on transformer terminals or reduce
load. Check connections. Check conductors for proper
size.
Starting load too high Check what load motor is supposed to carry at start.
Broken impeller blade(s) or
loose impeller Look for cracks near the rings. A new impeller may be
required as repairs are usually temporary.
Open primary circuit Locate fault with testing device and repair.
Motor takes too long to
accelerate
Excess loading Reduce load.
Poor circuit Check for high resistance.
Defective motor Replace with new motor.
Applied voltage too low Get power company to increase power tap.
Wrong rotation Wrong sequence of phases Reverse connections at motor or at switchboard.
Motor overheats while
running under load
Overloaded Reduce load.
Frame or bracket vents may
be clogged with dirt and
prevent proper ventilation of
motor
Open vent holes and check for a continuous stream of air
from the motor.
Motor may have one phase
open
Check to make sure that all leads are well connected.
Grounded coil Locate and repair.
Unbalanced terminal voltage Check for faulty leads, connections and transformers.
Troubleshooting
Your motor service and any troubleshooting must be handled by qualified persons who have proper tools and
equipment.
9 Vane Axial Fans
®