What can cause the ATV12 to show a Process Overload fault, OLC?


28 July 2022


Product Line:
Altivar 12

All models

Customer is doing 6 cycles per minute (start/stop) and noticed that after 3 cycles the drive will show "OLC"

OLC is process overload.
Check the process and the parameters of the drive.
Go to I_O- menu:
Parameter tOL is the Application Overload time delay, adjustable range 0-100sec.
Parameter LOC is the Application Overload threshold, adjustable range 70-150% of Motor rated current nCr.

This function can be used to stop the motor in the event of an application overload. This is not a motor or drive thermal overload. If the motor current exceeds the Application Overload threshold LOC, an Application Overload time delay tOL is activated. Once this time delay tOL has elapsed, if the current is still greater than the overload threshold LOC -10%, the drive will stop running and display OLC, Process overload.
Overload detection is only active when the system is in steady state (speed reference reached).
tOL = 0 will deactivate application overload detection.