User`s manual

Troubleshooting
9
9-8
9. Troubleshooting
Alarm
No.
Alarm name Possible cause Checkpoint Action Reset
E20
Control
power
undervoltage
Control circuit power
supply voltage is low.
Check the power supply
system.
Increase the power
supply voltage.
C
A unit in the power
supply system is
drawing a heavy
current that lowers the
voltage while that unit
is operating.
Isolate the power supply
system into separate
units and the robot driver.
A
Chattering in
electromagnetic
contactor on power
supply side
Replace the
electromagnetic
contactor.
Poor connection in
power supply system
Repair the poor
connection.
Insufficient power
supply capacity
Provide larger power
supply capacity.
Control circuit power
supply voltage is
lowered.
A momentary power
failure occurred.
Check if the symptom
shown at left has occurred.
After clearing the tripped
alarm, restart operation.
C
E21
Robot driver
overheat
The load is too heavy. Check the load.
Check the ambient
temperature.
• Clear the tripped alarm
after the robot driver
cools down, or lower the
ambient temperature.
B or C
Ambient temperature
of robot driver is higher
than 55°C.
Motor shaft is locked. Visual check. Unlock the motor.
A
The duty ratio of the
built-in regenerative
braking resistor is high.
Check the regenerative
capacity.
Use an external braking
resistor.
E22 CPU error 2
Microcomputer in
robot driver cannot
communicate due to
noise.
Check if there is any noise
source (including a solenoid
coil and electromagnetic
contactor) near the robot
driver.
• Isolate the noise source
away from the robot
driver.
• Install a noise filter or
surge absorber.
A
Problem in
communication circuit
Turn off and on the power
supply again and check the
condition.
If the circuit is defective,
contact us for repair.
E25 Overtravel
Wrong terminal
connection
Check the cable connection. Correct the cable
connection.
A
FOT/ROT terminals
were not ON (closed)
at servo-on.
Check if the FOT/ROT
terminals are ON, by
viewing the Input terminal
monitor d-05.
Turn on both or at least
one terminal of the FOT
and ROT terminals.
C
Letters in the Reset column:
A: Shut off the power to the robot driver, perform troubleshooting, replace or repair defective parts.
B: After the robot stops, wait until the robot driver cools. Then short RS to P24, and perform troubleshooting.
C: After the robot stops, short RS to P24, and perform troubleshooting or shut off the power.