Xylem HYDROVAR Smart Manuel Opérateur page 7

Furthermore, care must be taken not to short circuit the neighbouring
components when connecting the external control wires and that open
cable ends which are not in use are isolated.
The HYDROVAR-SMART control unit contains electronic safety devices
which switch off the frequency drive in the event of faults, whereby the
motor has zero current but remains energised and comes to a halt. The
motor can also be halted by mechanical blocking. If it is switched off
electronically the motor is disconnected from the mains voltage
through the electronics of the frequency converter but is not potential-
free in the circuit.
In addition voltage fluctuations, especially power failures can cause the
system to switch off itself.
Repair of faults can cause the motor to start up again!
The system is only allowed to be put into operation when it has been earthened. In
addition, efficient grounding of all pipes must be ensured.
The operating instructions must be read, understood and followed by the operating
personnel. We point out that we accept no liability for damage and operating disorders
which are the result of non-compliance with the operating instructions.
7