No. of Earth bar of switchboard 1

[kimseunghee]

The 6.6kV switchboard consists of 20 cubicles having earth bar and each earth bar is connected with each other, i.e same potentail is kept between each cubicle. In order to earth to ground, dedicated cable to connected to ground from earth bar at each cubicle, 20 earth cable. But, I think 20 earth cables are not necessary, because it is same potential.
Therefore, I think one earth cabling is at each end of cubicle. This means two earth cables are connected to grounds.
Is my proposal O.K ? If any rules state how many earths are required, please let me know.

 

[Marmite]

The normal earthing arrangement for a multi panel switchboard with an integral earth bar running along between panels would be a separate earth cable from each end of the board marshalled onto a common copper earth bar. The main substation earth cable is also connected onto the earth bar. Some designs of switchgear require the removal of sections of earthing to get to the cable box to make off cables, in which case it is extremely important to earth both ends of the switchboard.
Regards
Marmite

 

[slavag]

Hi.
As Marmite saied. ( for all voltage levels)
Regards.
Slava

 

[rovineye]

And if the earth cables are sufficient size to carry fault current.