Delta VFD037CP43B-21

Chapter 1 IntroductionCP2000
1-7
Asymmetric Ground System (Corner Grounded TN Systems)
Caution:
Do not remove the RFI jumper while the input terminal of the Power Regenerative Unit carries power.
In the following four situations, the RFI jumper must be removed. This is to prevent the system from
grounding through the RFI capacitor and damaging the Power Regenerative Unit.
RFI jumper must be removed
1. Grounding at a corner in a triangle configuration
L2
L3
L
1
Figure 1-9
2. Grounding at a midpoint in a polygonal
configuration
L2
L
3
L
1
Figure 1-10
3. Grounding at one end in a single-phase
configuration
L
1
N
Figure 1-11
4. No stable neutral grounding in a three-phase
autotransformer configuration
L1
L2
L3
L1
L2
L3
Figure 1-12
RFI jumper can be used
Internal grounding through RFI capacitor, which reduces
electromagnetic radiation. In a situation with higher
requirements for electromagnetic compatibility, and using
a symmetrical grounding power system, an EMC filter can
be installed. As a reference, the diagram on the right is a
symmetrical grounding power system.
L2
L3
L1
Figure 1-13