Earthing The Switchgear - Siemens NXAIR Installation Instructions Manual

Assembling the panels
Fig. 127: Connection compartment of the adjacent panel, rear view
✓
The interconnections of the earthing busbar are completed.

7.11 Earthing the switchgear

To earth the switchgear row, connect at least the earthing busbar of the left and right end
panel to the substation earth of the switchgear building. The connection is available in every
panel in the connection compartment.
100
INFORMATION
The solid connection of the earthing busbar with the substation earth of the
switchgear building can also be tested with 100 A DC.
The test must be done from the left end panel and the right end panel, via the
switchgear row to the substation earthing point with 100 A DC, and the result must
be < 200 µΩ.
If the resistance from the earthing bar in the end panels to the substation earthing
point is given with < 200 µΩ, there is no need for an additional earthing connection
to the substation earth in every fifth panel.
NXAIR /
≤
40 kA 110-0084.9 / 15