substation perimeter block wall
substation perimeter block wall
(OP)
A concrete block wall makes up a portion of a distribution substation perimeter. The wall's purpose might be just to reduce the visual impact on one side, or it may be part of a control building that intersects the fence. In either case, the outside of the wall can be contacted by neighbors or by the general public without entry of the station. The ground grid extends several feet beyond the substation perimeter, including the block wall portion. The wall is reinforced with vertical an horizontal rebar which is not bonded together or bonded to the ground grid. Do you see a hazard here? Thanks.






RE: substation perimeter block wall
There may be a hazard if there are overhead lines that could fall on the wall and energize it without providing a low impedance path for fault current. Barbed wire on top, bonded to the ground grid, would solve that possible hazard.
RE: substation perimeter block wall
However, I am not clear regarding the comment about line fall. I believe that Will be a hazard situation regardless the wall ground impedance. The protection system should detect as a fault a broken line and instant later after hit the wall or the earth.
Often a substation fence includes an isolation panel to limit the transfer potential of neighbor property fence.
RE: substation perimeter block wall