Troubleshooting Of Warnings; Motor - YASKAWA E-V Series User Manual

9.2.2 Troubleshooting of Warnings

Refer to the following table to identity the cause of a warning and the action to be taken. Contact your
Yaskawa representative if the problem cannot be solved by the described corrective action.
Warning
Warning Name
Display
Position Error
A.900
Pulse Overflow
Position Error
Pulse Overflow
A.901
Alarm at Servo
ON
Overload:
Warning before
alarm A710 or
A720 occurs
In either of the fol-
lowing cases:
1. 20% of the
overload
A.910
detection level
of A710 was
reached.
2. 20% of the
overload
detection level
of A720 was
reached.
A.911 Vibration
Situation at Warning
Occurrence
Wiring of the servomo-
Check the wiring of the cable for
tor U, V, or W line is
motor main circuit.
incorrect.
The SERVOPACK gain
Check the SERVOPACK gain.
is too low.
The position reference
Lower the position reference pulse
pulse frequency is too
frequency.
high.
The position reference Lower the position reference accelera-
acceleration is too high. tion.
The excessive position
error alarm level
Check the excessive position error
(Pn520) is too low for
alarm level (Pn520).
the operating condi-
tions.
A SERVOPACK fault
−
occurred.
When the servo was
OFF, the servomotor
moved without clearing
position error pulses Check the error counter (Un008).
and excessive position
error pulses accumu-
lated.
The servomotor or
encoder wiring is incor-
Check the wiring.
rect or the connection is
faulty.
The servomotor is in
excess of the overload Check the overload characteristics of
protective characteris- the servomotor and reference input.
tics.
The servomotor is not
driven due to a mechan-
Check the reference input and motor
ical factor and the oper-
speed.
ating load has become
excessive.
A SERVOPACK fault
−
occurred.
Check whether unusual sound is gen-
Unusual vibration was
erated from the motor, and check the
detected while the
speed, and force waveform of the
motor was moving.

motor.

The mass ratio (Pn103)
is larger than the actual
Check the mass.
value or greatly
changes.
Cause
Check whether there is any loose con-
nection in motor wiring or encoder
wiring.
Increase the speed loop gain (Pn100)
or position loop gain (Pn102).
Lower the position reference pulse
frequency or the position reference
acceleration, or correct the electronic
gear ratio.
Apply a smoothing function, such as a
position reference acceleration/decel-
eration time constant (Pn216).
Set an appropriate value for the
Pn520.
Turn the power supply OFF and then
ON again. If the alarm still occurs, the
SERVOPACK may be faulty. Repair
or replace the SERVOPACK.
Make a setting to clear position error
pulses when the servo is OFF or set an
appropriate value for the excessive
position error alarm level (Pn520).
Correct the servomotor and encoder
wiring if they are wrong.
Reconsider the load and operation
conditions.
Or, check the servomotor capacity.
Improve the mechanical factor.
The SERVOPACK may be faulty.
Repair or replace the SERVOPACK.
Lower the motor movement speed or
the speed loop gain (Pn100).
Set an appropriate value for the mass
ratio (Pn103).
9.2 Warning Displays
Corrective Actions
9-21
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