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6. TROUBLESHOOTING
6-6
6.2 Motor operation out of ordinary
If any of the following faults has occurred in the motor, find out its cause and take
adequate measures.
Event Check Point
Possible Cause (
)
and
Corrective Action (
•
)
Check the main
circuit.
A normal power supply voltage is not applied.
The jumper across terminals P/+-P1 has been
disconnected.
The motor is not wired properly.
The switch connected between the motor and
drive unit is open.
Check the control
signals.
The start signal has not been initiated.
Both the forward and reverse rotation signals
are input.
The speed setting signal is not input.
The MRS signal remains ON.
Check the
parameter
settings.
The reverse rotation prevention, Pr. 78 [Section
8.5.1], value has been set.
0 was set as the maximum speed, Pr. 1 [Section
8.5.1], value.
Check the load.
The load is too heavy.
(The alarm message OL appears.)
The motor shaft is locked.
Motor remains
stopped.
Others
The alarm lamp is lit.
The POWER lamp is off.
Terminals PC and SD are shorted.
Check the main
circuit.
The wiring of the motor connection terminals U,
V, W does not match the motor phase sequence.
Motor rotates in
opposite
direction.
Check the control
signals.
The wiring of the forward rotation signal
(terminal STF) and that of the reverse rotation
signal (terminal STR) was exchanged.
Check the control
signals.
The speed settin
g
si
g
nal differs from the settin
g
.
The speed setting signal is compounded with noise.
Speed differs
from the settin
g
.
Check the
parameter
settings.
The speed signal bias/gain, Pr. 902, Pr. 903
[Section 8.3.1], values have been set.
The maximum speed, Pr. 1 [Section 8.5.1],
value or minimum speed, Pr. 2 [Section 8.5.1],
value has been set.
The stall prevention function was activated.
•
Increase the acceleration or deceleration time
setting.
•
Reduce the load.
Acceleration/
deceleration is
not smooth.
Check the
parameter
settings.
The stall prevention function was activated.
•
Increase the acceleration or deceleration time
setting.
•
Reduce the load.
Check the control
signals.
The speed setting signal varies.
Speed varies.
Check the load.
The load varies.
At start, motor
shaft runs in
opposite
direction
instantaneousl
y
.
Check the
parameter
settings.
The acceleration time setting is more than that
for the maximum permissible starting torque.
•
Increase the acceleration time setting.
•
Reduce the stall prevention operation level in
Pr. 22.