Yaskawa MP940 - Manual (Page 398)

10.2 Troubleshooting
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10.2.2 Troubleshooting Problems with No Alarm Display
Refer to the tables below to identify the cause of a problem which causes no alarm display
and take the remedy described.
Turn OFF the servo system power supply before commencing the shaded procedures.
Contact your Yaskawa representative if the problem cannot be solved by the described pro-
cedures.
Table 10.4 Troubleshooting Table No Alarm Display
Symptom Cause Inspection Remedy
Servomotor Does Not
Start Power not connected Check voltage between power
supply terminals. Correct the power circuit.
Loose connection Check terminals of connectors
(CN1, CN2). Tighten any loose parts.
Connector (CN1) external wir-
ing incorrect Check connector (CN1) exter-
nal wiring Refer to connection diagram and
correct wiring.
Servomotor or encoder wiring
disconnected. Reconnect wiring
Overloaded Run under no load. Reduce load or replace with larger
capacity servomotor.
Speed/position references not
input Check reference input pins. Correctly input speed/position ref-
erences.
/S-ON is turned OFF Check settings of parameters
Pn50A.0 and Pn50A.1. Turn /S-ON input ON.
/P-CON input function setting
incorrect Check parameter Pn000.1. Refer to 6.4.2 Function Selection
Constants and set parameters to
match application.
Reference pulse mode selection
incorrect. Refer to 6.4.4 Position-related
Parameters for parameter
Pn200.0 Correct setting of parameter
Pn200.0.
Encoder type differs from
parameter setting. Incremental or absolute
encoder? Set parameter Pn002.2 to the
encoder type being used.
P-OT and N-OT inputs are
turned OFF. Turn P-OT and N-OT input sig-
nals ON.
CLR input is turned ON Check status of error counter
clear input. Turn CLR input OFF.
SEN input is turned OFF. When absolute encoder is used. Turn SEN input ON.
Servomotor Moves
Instantaneously, then
Stops Servomotor or encoder wiring
incorrect. Refer to 5.4 Connecting Periph-
eral Devices, 5.5 SERVOPACK
Main Circuit Connection, and 5.6
SERVOPACK I/O Signals and cor-
rect wiring.
Suddenly Stops during
Operation and will Not
Restart Alarm reset signal (/ALM-
RST) is turned ON because an
alarm occurred. Remove cause of alarm. Turn
alarm reset signal (ALM-RST)
from ON to OFF.
Servomotor Speed
Unstable Wiring connection to motor
defective Check connection of power
lead (phases U, V, and W) and
encoder connectors. Tighten any loose terminals or
connectors.