YASKAWA SGDV User Manual page 281

9 Troubleshooting
Problem
Overtravel (OT)
Improper Stop
Position by
Overtravel (OT)
Signal
9-22
Probable Cause
Forward or reverse run prohibited
signal is input.
Forward or reverse run prohibited
signal malfunctioning.
Incorrect forward or reverse run
prohibited signal (P-OT/N-OT)
allocation (parameters Pn50A.3,
Pn50B.0)
Improper limit switch position and
dog length
The overtravel limit switch position
is too short for the coasting
distance.
Investigative Actions
Check the external power supply
(+24 V) voltage for the input signal.
Check if the overtravel limit switch
operates properly.
Check if the overtravel limit switch
is wired correctly.
Check the settings for parameters
Pn50A and Pn50B.
Check the fluctuation of the exter-
nal power supply (+24 V) voltage
for the input signal.
Check if the overtravel limit switch
operates correctly.
Check if the overtravel limit switch
wiring is correct. (check for dam-
aged cables or loose screws.)
Check if the P-OT signal is allo-
cated in Pn50A.3.
Check if the N-OT signal is allo-
cated in Pn50B.0.
−
−
(cont'd)
Corrective Actions
Correct the external power supply
(+24 V) voltage.
Correct the overtravel limit switch.
Correct the overtravel limit switch
wiring.
Correct the settings for parameters
Pn50A and Pn50B.
Stabilize the external power supply
(+24 V) voltage.
Correct the overtravel limit switch.
Correct the overtravel limit switch
wiring.
If another signal is allocated in
Pn50A.3, allocate P-OT.
If another signal is allocated in
Pn50B.0, allocate N-OT.
Install the limit switch at the
appropriate position.
Install the overtravel limit switch at
the appropriate position.