Standstill monitoring of AC drives
The new Wieland Electric SVM 4001K monitors have been specifically designed for the safe standstill monitoring of all AC drives without the need for any additional sensors.
This Back EMF safe standstill detection with the SVM 4001K monitors is achieved by the evaluation of the induced residual voltage during the run down of one-or three-phase AC motors.
The SVM 4001K monitor is connected directly to the supply voltage connections of the AC motor.
If this voltage exceeds the adjusted threshold voltage at the terminals L1, L2 and L3 of the device, the relay contacts open instantaneously.
However, if the monitored voltage falls below the adjusted threshold voltage during the run down of the AC motor in question, the output relay is turned on after an adjustable delay.
The monitors come with TUV approval and are suitable for use up to PL e / category 4 or SIL 3. The UL approval for the device is pending.