Safe Torque Off 6-34 
AC30V series Variable Speed Drive 
Troubleshooting 
Symptom 
Probable cause  Remedy 
GKP display 
6
User inputs 
7
 
Drive won’t start when 
given a start 
command 
*** TRIPPED *** 
SAFE TORQUE OFF 
On  Both < 15V  STO is invoked. 
When safe to do so, connect X10/01 and 
X10/03 to 24V ± 10% 
*** TRIPPED *** 
SAFE TORQUE OFF 
Off 
Both >15V and < 
30V 
Fault latch might have 
tripped 
Remove all power from drive and re-apply. If 
symptom persists, immediately return the 
AC30V for repair. 
See the DANGER box below. 
Any other trip message, e.g. 
overvoltage 
Off 
Both >15V and < 
30V 
Drive is tripped, but not 
due to STO.  
Reset the trip, and remove its cause. If 
symptom persists, return the AC30V for repair. 
Any other message  Off 
Both >15V and < 
30V 
Faulty hardware  Return for repair 
Drives starts 
unexpectedly 
Don’t care  Don’t care  Both < 5V  Faulty hardware 
Immediately return the AC30V for repair. 
See the DANGER box below. 
Don’t care  Off  Both > 5V 
STO not invoked by 
the user. 
Use STO according to instructions elsewhere in 
this chapter. 
Drive fails 
comprehensive or 
regular STO test 
Don’t care  Don’t care  Don’t care  Faulty hardware 
Immediately return the AC30V for repair. 
See the DANGER box below. 
The table above is only a guide. It may not be a comprehensive list of all possible symptoms relating to STO. Parker will not accept responsibility for any 
consequences arising from its incompleteness or inaccuracy. 
 
Important note:  
•  There are no user-serviceable parts in the AC30V drive. Refer to the Safety Warnings and Limitations section on page 6-18 of this chapter. 
 
 
  
6
 Continuity through X10/05 and X10/06 
7
 Measure X10/01 and X10/03 relative to X10/02 or X10/04