Delta C2000 Series User Manual page 10

Isolating main power from ground:
When the power distribution system of the Power Regenerative Unit is a floating ground system (IT) or an
asymmetric ground system (TN), the RFI short short-circuit cable must be cut off. Cutting off the
short-circuit cable cuts off the internal RFI capacitor (filter capacitor) between the system's frame and the
central circuits to avoid damaging the central circuits and (according to IEC 61800-3) reduce the ground
leakage current.
Important points regarding ground connection
To ensure the safety of personnel, proper operation, and to reduce electromagnetic radiation, the
Power Regenerative Unit must be properly grounded during installation.
The diameter of the cables must meet the size specified by safety regulations.
The shielded cable must be connected to the ground of the Power Regenerative Unit to meet safety
regulations.
The shielded cable can only be used as the ground for equipment when the aforementioned points
are met.
When installing multiple sets of Power Regenerative Units, do not connect the grounds of the Power
Regenerative Units in series. As shown below.
Pay particular attention to the following points:
After turning on the main power, do not remove the RFI jumper while the power is on.
Make sure the main power is turned off before removing the RFI jumper.
Removing the RFI jumper will also cut off the conductivity of the capacitor. Gap discharge may occur
once the transient voltage exceeds 1000V.
If the RFI jumper is removed, there will no longer be reliable electrical isolation. In other words, all
controlled input and outputs can only be seen as low-voltage terminals with basic electrical isolation.
Also, when the internal RFI capacitor is cut off, the Power Regenerative Unit will no longer be
electromagnetic compatible.
The RFI jumper may not be removed if the main power is a grounded power system.
The RFI jumper may not be removed while conducting high voltage tests. When conducting a high
voltage test to the entire facility, the main power and the motor must be disconnected if 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 30 ) 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.
Ground terminal
Wrong wiring setup for ground wires
Chapter 1 Introduction
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