Ship unloader, "power inhabit " OC/OFF2"

Dear all,

I have a problem in my equipment, its a ship unloader, i face this problem each time at crane operation. 

When the operator closes the grab it closes little and comes to halt and if he resets his joy stick it works fine , every time he has to do it at each operation. 

the motor is using siemens sinamics drive S120. 

It says "power inhabit " OC/OFF2" I tried to Flyrestart but no changes.. can any one please give remedy for this issue.

and if the joy stick is reset it works fine..

Waht may be possible reason for this off2. Pls expalin

Thanks

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Split from What is OFF1, OFF2 and OFF3.