Siemens SINAMICS G220 - Page 176

Requirement
WARNING
Fire or electric shock due to unsuitable residual-current devices
The converter can generate a current through the protective conductor. The current through
the protective conductor can cause false tripping of the residual-current device or residual-
current monitoring device. In the event of a ground fault, the fault current can contain a DC
component that prevents the desired tripping of the residual-current device or residual-current
monitoring device, resulting in a 󹪝re or electric shock.
• Use the protective and monitoring devices recommended in the documentation.
If the earth-fault loop impedance of the line supply at the infeed point is too high to ensure
that the overcurrent protective device disconnects within the stipulated time in the case of
insulation failure (ground fault, fault to frame), then you must use additional residual current
devices RCD, type B.
To prevent tripping of the residual current device due to operational leakage currents, the
following requirements must be met:
• The neutral point of the line supply system is grounded.
• The motor cables are shorter than 50m (164ft) shielded, or 100m (328ft) unshielded.
• Each converter must be provided with its own designated residual-current device.
Connecting
7.1Line system, motor and braking resistor
SINAMICS G220 converter
174 Operating Instructions, 04/2024, FW V6.2, A5E51781573B AB