Chapter 2 Wiring | VFD-VJ
2-10
Floating Ground System (IT Systems)
A floating ground system is also called IT system, ungrounded system, or high impedance/resistance
(greater than 30Ω) grounding system.
Disconnect the ground cable from the internal EMC filter.
In situations where EMC is required, check whether there is excess electromagnetic radiation
affecting nearby low-voltage circuits. In some situations, the adapter and cable naturally provide
enough suppression. If in doubt, install an extra electrostatic shielded cable on the power supply side
between the main circuit and the control terminals to increase security.
Asymmetric Ground System (Corner Grounded TN Systems)
Caution: Do not remove the RFI switch while the input terminal of the hybrid servo drive carries
power. In the following four situations, the RFI switch must be removed. This is to prevent the system from
grounding through the RFI capacitor and damaging the hybrid servo drive
Remove the RFI switch
1. Corner-Grounded Delta System)
2. Center-Tap Grounded Delta System)
3. Single Phase with Ground)
4. Delta System without Ground)