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11.6.4 Grounding configuration with corner-grounded delta-input
If a phase of delta-input source is grounded (B-phase for example), the ground bus in the UPS cabinet
should NOT be connected to the neutral terminal of UPS output. So, the jumper cable should be
disconnected. See Figure 11.9 for the jumper cable location.
The UPS output is floating against ground during normal operation. An isolation transformer is
recommended at output distribution as shown in Figure 11.12.
Figure 11.12 - Grounding configuration with corner-grounded delta-input.
N
G
3
φ
3
φ
3
φ
N
G
< UPS Cabinet >
G
N
3
φ
3
φ
To the
Load
Output Distribution
3
φ
3
φ
G
Input Source
B
φ
Disconnect
The Cable
