Delta C2000 Series User Manual page 16

Isolating main power from ground:
When the power distribution system of the drive is a floating ground system (IT Systems) or an asymmetric
ground system (Corner Grounded TN Systems), you must remove the RFI jumper. Removing the RFI
jumper disconnects the internal capacitors from ground to avoid damaging the internal circuits and to
reduce the ground leakage current.
Important points regarding ground connection
 To ensure the safety of personnel, proper operation, and to reduce electromagnetic radiation, you must
properly ground the drive during installation.
 The diameter of the cables must comply with the local safety regulations.
 The shield of shielded cables must be connected to the ground of the drive to meet safety regulations.
 The shield of shielded power cables can only be used as the ground for equipment when the
aforementioned points are met.
 When installing more drives, do not connect the grounds of the drives in series but connect each drive
to ground. The following pictures show the correct and wrong ways to connect the grounds.
Pay particular attention to the following points:
 Do not remove the RFI jumper while the power is on.
 Removing the RFI jumper also disconnects the built-in EMC filter capacitors. Compliance with the EMC
specifications is no longer guaranteed.
 Do not remove the RFI jumper if the mains power is a symmetrical grounded power system in order to
maintain the efficiency for EMC circuit.
 Do not remove the RFI jumper while conducting high voltage tests. When conducting a high voltage
test to the entire facility, you must disconnect the mains power and the motor if the leakage current is
too high.
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.
 Do not install an external RFI/EMC filter, the EMC filter will pass through a filter capacitor, thus
connecting power input to ground. This is very dangerous and can easily damage the Power
Regenerative Unit.
Figure 1-8
1-7
Chapter 1 IntroductionC2000
Figure 1-9