Safe Torque Off
6-28
AC30V series Variable Speed Drive
Comprehensive Check
A comprehensive check of the STO function ensures the overall integrity of the STO functionality. It proves the independent operation of each channel
individually (including during the normal dual channel operation), the STO user feedback operation, and the essential single fault detection.
It must always be performed:
During factory test
During commissioning activities
After repair or replacement of the AC30V
After any hardware or software design changes which may affect the AC30V concerned.
After each intervention into the system and control wiring.
At defined maintenance intervals as determined by the machine builder and /or user risk assessments and associated verification
assessments.
If the machine has been idle for more than a period of time determined by the machinery builder and user risk assessments.
The check must be made by suitably qualified professional personnel following all necessary safety precautions. They must be fully conversant with all
equipment concerned.
NOTE
: In the following text where it is required that “all power” is removed. Remove power and wait 5 minutes.
The performance of the individual test steps of the STO function should be logged.
WARNING
DURING THIS TEST, THE SAFETY FUNCTION MUST NOT BE RELIED ON BECAUSE AT TIMES ONLY ONE CHANNEL WILL BE
ACTIVATED AND THEREFORE THE INTENDED SAFETY FUNCTION MAY NOT BE AVAILABLE.
ALSO STO WILL BE ACTIVATED WHILE THE MOTOR IS ROTATING, WHICH IS NOT THE NORMAL OPERATION.
THEREFORE THE USER MUST ENSURE IT IS SAFE TO DO THIS TEST BY USING AN APPROPRIATE RISK ASSESSMENT AND
TAKING ANY ADDITIONAL RISK REDUCTION MEASURES.
