5 Troubleshooting
5
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Cause
Confirming Methods
Corrective Action
10. The servo drive is faulty.
-
Replace a new servo drive.
Er.922: Resistance of external braking resistor too small
Cause
Confirming Methods
Corrective Action
When an external
regenerative resistor is used
(H02-25 = 1 or 2), resistance
of the external regenerative
resistor is smaller than
minimum value required by
servo drive.
Measure resistance of the external
regenerative resistor between
P
and
C and check whether it is smaller
than H02-21 (allowed minimum
value of regenerative resistor).
If yes, connect an external regenerative
resistor matching servo drive between
P
and C and set H02-27 (resistance of
external regenerative resistor) to resistance
of the selected regenerative resistor.
If not, set H02-27 to resistance of the
selected regenerative resistor.
Er.939: Motor power cable breaking
Cause
Confirming Methods
Corrective Action
Motor power
cable breaking
Check whether difference between H0B-24 (phase current
valid value) and H0B-02 (internal torque reference)
reaches over 500%. Meanwhile, H0B-00 (actual motor
speed) is smaller than one fourth of rated motor speed.
Check the motor power cable
connection and reconnect wirings. If
necessary, replace a new cable.
Er.941: Parameter modification taking effect only after re-power-on
Cause:
Modification of some parameters takes effect only after servo drive is powered on again. After these
parameters are modified, servo drive reminds of re-power-on.
Cause
Confirming Methods
Corrective Action
Modify parameters, whose modification
takes effect only after re-power-on.
Check whether you modify parameters,
whose modification takes effect only after
re-power-on.
Re-power on the servo
system.
Er.942: Parameter storage too frequent
Cause
Confirming Methods
Corrective Action
A great number of parameters are
modified and stored frequently to
EEPROM (H0C-13 = 1).
Check whether host controller
performs frequent and fast
parameter modification on servo
drive.
Check the running mode. For the
parameters that need not be stored
in EEPROM, set H0C-13 to 0 before
writing operation of host controller.
Er.950: Forward limit switch warning
Cause
Confirming Methods
Corrective Action
Logic of DI set for
FunIN.14: P-OT (forward
limit switch) is valid.
Check whether a parameter in group H03
is set for FunIN14 (P-OT).
Check whether logic of corresponding DI
is valid in H0B-03 (monitored DI states).
Check the running mode. Send a
reverse reference or rotate motor on the
prerequisite of ensuring safety to make
logic of the forward overshoot switch
terminal invalid.