
APPENDIX
B–64124EN/01
G. ALARM LIST
883
No. CountermeasureDescriptionLED display
A DC link overvoltage alarm is issued. This alarm is issued when the DC voltage of the
main circuit power is too high.
(1) When SVU–12 or SVU–20 is used, and a separate regenerative discharge unit is not used,
check the specification to see if regenerative energy per one time does not exceed the allow-
able regenerative energy of the servo amplifier unit.
(2) For the SVU–40 and the SVU–80, when the separate regenerative discharge resistor is not
used, check whether the CX23 connector is short–circuited with a dummy connector.
(3) The supply voltage for dynamic power may exceed the rated value. Check the voltage. If the
voltage is too high, reduce the voltage to an appropriate level.
(4) The regenerative discharge unit may not be properly connected. Check the connection.
(5) The resistance of the separate regenerative discharge unit may be abnormal. Disconnect the
separate regenerative discharge unit, then check the resistance. If the resistance is not within
(20% of the predetermined resistance, replace the separate regenerative discharge unit.
(6) If (1) to (5) are not the cause of the alarm, replace the servo amplifier unit.
A DC link low voltage alarm is issued. This alarm is issued when the DC voltage of the
main circuit power is too low.
(1) 190 ms or longer may pass from the time when both the *ESP of the built–in DI and the *ESP
of the I/O link interface signal are canceled until the external magnetic contactor inserted into
the input for motive power turns on(including the operating time of the magnetic contactor).
The magnetic contactor must turn on within 100 ms.
(2) The external circuit breaker may be turned off. Check the circuit breaker.
(3) The supply voltage for dynamic power is lower than the rated value. Check the voltage. If the
voltage is too low, increase it to an appropriate level.
(4) The external magnetic contactor may not be connected properly. Check the connection.
If (1) to (4) are not the cause of the alarm, replace the servo amplifier unit.
417
A parameter has been specified incorrectly. Check the following parameters:
No.30: Is the specified motor type correct?
No.31: Is the specified direction of rotation of the
motor correct?
No.106: Is the denominator of the number of
pulses per single revolution of the motor 0?
No.180: Is the specified reference counter ca-
pacity 0 or a negative value?
418
A DO alarm is issued. Replace the servo amplifier unit.
423
The specified speed exceeds 32767000
detection units per second.
Re–examine the CMR and speed settings.
The cooling fan has stopped. This alarm is issued when the fan motor built into
the servo amplifier unit has failed.
The fan motor is consumable.
(1) Check that the fan is not clogged with something.
(2) Check that the power connector of the fan is connected properly.
(3) Replace the fan or servo amplifier unit.
446
The external pulse input line is disconnected. Connect the external pulse input signal correctly.
447
The velocity deviation is too high (velocity con-
trol)
Check the actual velocity.
See the settings of parameter No. 136.