Yaskawa DR2 Sigma Servo - Manual (Page 421)

6.2 Troubleshooting
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6.2.2 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.
Troubleshooting Table No Alarm Display
Symptom Cause Inspection Remedy
Servomotor does not start Power not connected Check voltage across L1
and L2, L and N.
Correct the power circuit.
Loose connection Check terminals of
connectors (1CN, 2CN).
Tighten any loose parts.
Connector (1CN) external
wiring incorrect
Check connector (1CN)
external 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 input pins of
connector 1CN.
Correctly input
speed/position references.
S-ON is turned OFF Cn-01 Bit 0 is 0. Turn S-ON input ON.
P-CON input function setting
incorrect
Refer to Subsection 3.2.1. Refer to Subsection 3.2.1
and set user constants to
match application.
Reference pulse mode
selection incorrect.
Refer to Subsection 3.2.2. Select correct user
constants Cn-02 Bits 3, 4, 5.
Encoder type differs from
user constant setting.
Incremental or absolute
encoder?
Set user constants Cn-01 Bit
E to the encoder type used.
P-OT and N-OT inputs are
turned OFF.
(If Cn-01 Bits 2, 3 are 0) Turn P-OT and N-OT input
signals ON.
CLR input is turned ON Check status of error
counter clear input.
Turn CLR input OFF.
SEN input is turned OFF. Absolute encoder used with
Cn-01 Bit 1 set to 0.
Turn SEN input ON.
Servomotor moves
instantaneously, then stops
Number of encoder pulses
differs from user constant
setting.
2048 pulses/revolution or
1024 pulses/revolution
Set the user constant
(Cn-11) to match the number
of encoder pulses.
Servomotor or encoder
wiring incorrect.
Refer to Subsection 3.8.8
and correct 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 (U, V, and W phase)
and encoder connectors.
Tighten any loose terminals
or connectors.
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