Functions
5.8 Motor and inverter protection
Frequency inverter
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Operating Instructions, 08.10. 2008, t.b.d.
5.8.4
Load torque monitoring
Applications with load torque monitoring
In many applications, it is advisable to monitor the motor torque:
●
Applications in which the mechanical connection between the motor and load may be
interrupted (e.g. if the drive belt in fan or conveyor belt systems tears).
●
Applications that are to be protected against overload or locking (e.g. extruders or
mixers).
●
Applications in which no-load operation of the motor represents a critical situation (e.g.
pumps).
Load torque monitoring functions
The inverter monitors the torque of the motor in different ways:
1.
No-load monitoring:
The inverter generates a message if the motor torque is too low.
2.
Lock protection:
The inverter generates a message if the motor speed cannot match the speed setpoint
despite maximum torque.
3.
Stall protection:
The inverter generates a message if the inverter controller has lost the orientation of the
motor.
4.
Frequency-dependent torque monitoring:
The inverter measures the current torque and compares it with a parameterized
frequency/torque characteristic.