Troubleshooting By Symptom - Mitsubishi Electric MELSEC iQ-R Series User Manual

14.2
Troubleshooting when a motor does not rotate
Check items and corrective actions for troubleshooting when a motor does not rotate are described below.
Check item
Is the PLC READY signal [Y0] ON?
Is the servo amplifier powered ON?
Is there an error in the servo amplifier?
Is the wiring between the Motion module and servo amplifier
correct?
Is the wiring between the servo amplifier and motor correct?
Is the wiring of the limit signal correct?
Is there an error in the Motion module? (The ERR LED is ON
or flashing.)
Isn't the value in "[Md.26] Axis operation status" "1:
stopped"?
Is the value in "[Md.20] Feed current value" changed after
positioning control is performed?
Is the cumulative pulse of servo amplifier changed after
positioning control is performed?
If a motor does not rotate even after the above items are checked, the possible cause is a hardware failure.
Please consult your local Mitsubishi representative, explaining a detailed description of the problem.
Troubleshooting when a motor does not rotate as intended
Check items and corrective actions for troubleshooting when a motor does not rotate as intended are described below.
■When a motor rotates only in the opposite direction
Check item
Is the setting of "Travel direction selection (PA14)" correct?
■When a motor does not rotate at the set speed
Check item
Does the value in "[Md.28] Axis feedrate"
speed?
*1 Speed control mode and continuous operation to torque control mode: "[Md.122] Speed during command"
■When the set position is not reached
Check item
Does the value in "[Md.20] Feed current value" indicate the
intended position when the motor stops?
14 TROUBLESHOOTING
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14.2 Troubleshooting by Symptom

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Troubleshooting by Symptom
*1
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Action
Review the program to turn ON the PLC READY signal [Y0].
Power on the servo amplifier.
Check the error code of the servo amplifier and take a corrective action.
Check the wiring between the Motion module and servo amplifier, and correct it.
Check the wiring between the servo amplifier and motor, and correct it.
Check the wiring and logic setting of the limit signal, and correct the wiring.
Check the error code and take a corrective action.
• Review the stop program.
• Review whether the stop signal (STOP) is not input erroneously.
Review the start program.
Refer to the manual of each servo amplifier and check if any function that suppress the motor
rotation is activated.
Action
Check the setting of "Travel direction selection (PA14)" to see if the intended rotation direction
has been set. Once "Travel direction selection (PA14)" is changed, power OFF and ON the
servo amplifier or reset the controller to return to the home position.
Action
*1
[When "[Md.28] Axis feedrate" indicates the set speed]
• Check that the values in "[Pr.2] Number of pulses per rotation (AP)", "[Pr.3] Movement
amount per rotation (AL)", and "[Pr.4] Unit magnification (AM)" meet the system.
• When the servo amplifier has the electronic gear function, check that the settings meet the
system.
*1
[When "[Md.28] Axis feedrate" does not indicate the set speed]
• Check that the speed is not limited by the value in "[Pr.8] Speed limit value".
• In the JOG operation, check that the speed is not limited by the value in "[Pr.31] JOG speed
limit value".
• In the JOG operation, check that Forward run JOG start signal [Cd.181] and Reverse run
JOG start signal [Cd.182] do not repeatedly turn ON and OFF.
Action
[When the position set in "[Md.20] Feed current value" is reached]
• Check that the values in "[Pr.2] Number of pulses per rotation (AP)", "[Pr.3] Movement
amount per rotation (AL)", and "[Pr.4] Unit magnification (AM)" meet the system.
• When the servo amplifier has the electronic gear function, check that the settings meet the
system.
[When the position set in "[Md.20] Feed current value" is not reached]
• Check that the motor is not stopped by Axis stop signal [Cd.180]. If a motor is stopped by the
stop command, the value "1: stopped" is stored in "[Md.26] Axis operation status".