The Stalled Motor Fault is a common cause of drives tripping out in web-handling applications. A stalled motor is usually serious. An example would be if an extruder faults on stalled motor. This could be because the resin is not melted or the screw is damaged.
While threading the line, the line speed is often set to zero with tension enabled. This can sometimes trigger a stalled motor fault. Even though the speed setpoint is zero and the encoder matches, the fault is still declared. The motor torque is controlled and nowhere near its limit, but the drive thinks it is stalled. This fault usually occurs many times while commissioning the line. It is predicable and should be inhibited during the design phase.
The stalled motor fault can usually be easily inhibited, but this calls for changing a default parameter in the drive. Depending on your drive you may need to:
- increase the minimum speed at which this fault is declared
- increase the time the motor must be stopped to declare this fault
- inhibit the fault entirely