Dedicated earthbar(I.E earth bar)

[kimseunghee]

Normally, the shield of instrument cable is locally earthed at local cabinet. However, some customer requires that all I.E cables for each earth bar of local cabinet be rought to dedicated/isolated earth bar from I.E bar of each local cabinet. The dedicated earh bar is insulated and dedicated cable is earthed.
What is difference between local earthing and dedicated earthing ?

 

[jghrist]

See

http://ecmweb.com/mag/electric_demystifying_isolated_grounding/index.html

and

http://ecmweb.com/mag/electric_demystifying_isolated_grounded/index.html,

Parts 1 & 2 of Demystifying Isolated Grounded Systems by Ken Michaels in Electrical Construction & Maintenance Magazine, March & April, 1999