35
COMMON
9. Troubleshooting
Whenever abnormality occurs in gearmotors or reducers, take sufficient measure immediately referring to Table 22 and 23.
Consult our nearest distributor or sales office when the unit does not recover after taking the measure.
Problem
Possible cause
Measure
Power failure
The motor will not operate under load.
The motor runs without a load but the output
shaft does not rotate.
When
a
load
is
applied
The
output
shaft
turns
without
a
load
The switch is heated.
Fuse tripping
The speed will not increase and the
motor is overheating.
The motor stops.
The motor runs in the reverse direction.
Fuse tripping
Excessive temperature rise
Oil
leakage
Leakage of oil / grease from input/output
shaft section
Leakage of oil / grease from the contact
surfaces of frame and outside cover
Leakage of oil / grease into motor
Abnormal sound
Abnormal vibration
Abnormal sound from motor
Contact the electric power company.
Defective electric circuit
Check the circuit.
Blown fuse
Replace the fuse with a new one.
Protective device is engaged
Disengage protective device.
Load locking
Check the load and safety device.
Poor switch contact
Adjust the contact area section.
Disconnection of motor stator coil
Return the unit to factory for servicing.
Bearing is broken
Return the unit to factory for servicing.
3-phase is functioning as single-phase.
Check the power supply with a voltmeter. Check
the motor, coil in the transformer, contactor, fuse,
etc. and repair or replace them.
Damage due to overloading of gears
Return the unit to factory for servicing.
Insufficient capacity of switch
Replace the switch with a specified one.
Overload
Decrease the load to the specified value.
Insufficient capacity of fuse
Replace the fuse with a specified one.
Overload
Decrease the load to the specified value.
Voltage drop
Contact the electric power company.
Overload
Decrease the load to the specified value.
Short-circuited motor stator coil
Return the unit to factory for servicing.
The key is missing
Install a key.
The bearing is burned.
Return the unit to factory for servicing.
Poor adjustment of protective device
Adjust the protective device.
Connection error
Change the connection.
The outlet wire is short-circuited.
Return the unit to factory for servicing.
Poor contact between motor and starter
Complete the connection.
Overload
Decrease the load to the specified value.
Voltage drop or voltage rise
Contact the electric power company.
The ambient temperature is high.
Improve the ventilation method.
Damaged bearing or gear
Return the unit to factory for servicing.
Damaged oil seal
Return the unit to factory for servicing.
Loose bolts
Tighten bolts correctly.
Damaged oil seal
Replace the oil seal with a new one.
Excessive oil / grease supply
Remove excess oil / grease.
Entry of dust and foreign matter into bearings or
damaged bearings.
Return the unit to factory for servicing.
Damaged gear.
Return the unit to factory for servicing.
Distortion of housing because the installation
surface is not flat
Make the installation base flat or make
adjustment using shims.
Resonance due to insufficient rigidity of
installation base
Reinforce the installation base to increase
rigidity.
Nonalignment of shaft with driven machine
Align the shaft centers.
Entry of foreign matter
Remove the foreign matter.
Damaged bearings
Return the unit to factory for servicing.
Transmission of vibration from the driven machine
Individually operate the gearmotor or reducer to
check the source of the sound.
Table 22 Troubleshooting
