YASKAWA SGD7S Product Manual page 529

12.4 Troubleshooting Based on the Operation and Conditions of the Servomotor
Problem
Overtravel
Occurred
Improper
Stop Posi-
tion for
Overtravel
(OT) Signal
12-60
Possible Cause
The P-OT/N-OT (Forward
Drive Prohibit or Reverse
Drive Prohibit) signal was
input.
The P-OT/N-OT (Forward
Drive Prohibit or Reverse
Drive Prohibit) signal mal-
functioned.
There is a mistake in the allo-
cation of the P-OT or N-OT
(Forward Drive Prohibit or
Reverse Drive Prohibit) sig-
nal in Pn50A = n.X or
Pn50B = n.X.
The selection of the Servo-
motor stopping method is
not correct.
The limit switch position and
dog length are not appropri-
ate.
The overtravel limit switch
position is too close for the
coasting distance.
Confirmation
Check the external power
supply (+24 V) voltage for
the input signals.
Check the operating con-
dition of the overtravel
limit switches.
Check the wiring of the
overtravel limit switches.
Check the settings of the
overtravel input signal
allocations (Pn50A/
Pn50B).
Check for fluctuation in
the external power supply
(+24 V) voltage for the
input signals.
Check to see if the opera-
tion of the overtravel limit
switches is unstable.
Check the wiring of the
overtravel limit switches
(e.g., check for cable
damage and loose
screws).
Check to see if the P-OT
signal is allocated in
Pn50A = n.X.
Check to see if the N-OT
signal is allocated in
Pn50B = n.X.
Check the servo OFF
stopping method set in
Pn001 = n.X or
Pn001 = n.X.
Check the torque control
stopping method set in
Pn001 = n.X or
Pn001 = n.X.
–
–
Continued from previous page.
Correction Reference
Correct the external
power supply (+24 V)
–
voltage for the input
signals.
Make sure that the
overtravel limit switches
–
operate correctly.
Correct the wiring of
the overtravel limit
page 5-32
switches.
Set the parameters to
page 5-32
correct values.
Eliminate fluctuation
from the external power
–
supply (+24 V) voltage
for the input signals.
Stabilize the operating
condition of the over-
–
travel limit switches.
Correct the wiring of
the overtravel limit
–
switches.
If another signal is allo-
cated in Pn50A
=n.X, allocate the
P-OT signal instead.
page 5-32
If another signal is allo-
cated in Pn50B
=n.X, allocate the
N-OT signal instead.
Select a Servomotor
stopping method other
than coasting to a stop.
page 5-34
Select a Servomotor
stopping method other
than coasting to a stop.
Install the limit switch at
the appropriate posi-
–
tion.
Install the overtravel
limit switch at the
–
appropriate position.
Continued on next page.