Fault
EF3 - External fault(terminal S3)
Cause
Thermal overload relay tripped due to motor overheat.
Remedy
Check the cooling water.
Fault
STO - Safe Torque Off function activated
Cause
The EMS button or motor thermal switch been triggered.
Remedy
If EMS is triggered, reset the button and reset the fault.
If motor thermal switch is triggered, check the wiring and cooling.
07/2021 - ©Atlas Copco
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Fault finding