Siemens SINAMICS G120 CU240B-2 - Speed and Load Failure Via Digital Input

Functions
7.7 Protection functions
Inverter with CU240B-2 and CU240E-2 Control Units
Operating Instructions, 07/2010, FW 4.3.2, A5E02299792B AA
183
7.7.7 Speed and load failure via digital input
With this function you can directly monitor not only the motor speed but also the speed of the
driven load. Examples include:
● Gearbox monitoring, e.g. in traction drives or hoisting gear
● Drive belt monitoring, e.g. in fans or conveyor belts
● Monitoring for blocked driven load
Speed or velocity monitoring functions
There are two ways of directly monitoring speed in your application:
1. Load failure monitoring: The inverter evaluates whether the sensor signal is present.
2. Speed deviation monitoring: The inverter calculates a speed from the signal of the
connected sensor and compares it with the internal motor control signal.
Speed monitoring requires a binary sensor (e.g. a BERO), the output signal from which is
evaluated as a pulse sequence by a digital input on the inverter.
Load failure monitoring
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Figure 7-6 Load failure monitoring by means of a digital input
If you parameterize the function of a digital input for load failure monitoring (P070x = 50), you
automatically interconnect this input to signal evaluation via BICO technology.