Delta VFD300C43S-HS User Manual page 15

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.
1. Grounding at a corner in a triangle configuration
Figure 1-7
3. Grounding at one end in a single-phase
configuration
Figure 1-9
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.
RFI jumper must be removed
2. Grounding at a midpoint in a polygonal
configuration
L 1
L 2
L 3
4. No stable neutral grounding in a three-phase
autotransformer configuration
L 1
N
RFI jumper can be used
1-7
Chapter 1 IntroductionC2000-HS
Figure 1-8
L 1
L 1
L 2
L 2
L 3
L 3
Figure 1-10
Figure 1-11
L 1
L 2
L 3
L 1
L 2
L 3