Delta C2000 Series User Manual page 10

Pay particular attention to the following points:
After turning on the main power, do not cut the RFI short-circuit cable while the power is on.
Make sure the main power is turned off before cutting the RFI short-circuit cable.
Cutting the RFI short-circuit cable will also cut off the conductivity of the capacitor. Gap discharge may
occur once the transient voltage exceeds 1000V.
If the RFI short-circuit cable is cut, 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 short-circuit cable may not be cut off if the main power is a grounded power system.
The RFI short-circuit cable may not be cut off 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.
Asymmetric Ground System(Corner Grounded TN Systems)
Caution: Do not cut the RFI short-circuit cable while the input terminal of the Power Regenerative Unit
carries power.
In the following four situations, the RFI short-circuit cable must be cut off. This is to prevent the system
from grounding through the RFI capacitor, damaging the Power Regenerative Unit.
1 Grounding at a corner in a triangle configuration
RFI short-circuit cable must be cut off
2 Grounding at a midpoint in a polygonal
configuration
L 1
L 2
L 3
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Chapter 1 Introduction C2000 Series
L 1
L 2
L 3