Bonding at subpanels

[csp2012]

This question concerns a large building with a grounding counterpoise, multiple bonding connection points to building steel, and ground bars in each electrical room. The electrical room ground bars are bonded to the overall grounding/counterpoise system.

All subpanels have equipment ground bars bonded to the panel enclosures. Each panelboard can is bonded to the electrical room ground bars, which are in turn bonded to the overall grounding system/counterpoise. Panelboard feeders include an appropriately sized ECG.

Is it acceptable to bond the equipment ground bars in the panelboards to the electrical room ground bars also?

 

[infinity]

I'm seeing more and more of this type of redundant grounding.
IMO some of it is a waste of money but I'm not paying. Code wise it's not an issue.

Welcome to the Forum.

 

[dnbob]

IMO, you are setting up parallel ground fault return paths.

 

[don_resqcapt19]

IMO, you are setting up parallel ground fault return paths.

There is no problem with having parallel fault return paths.

 

[tom baker]

IMO, you are setting up parallel ground fault return paths.

In a ground fault, most of thethe current will take the effective ground fault current path, which will be the EGC with the circuit conductors. Some current will take the ground fault current paths, which is all metallic paths in parallel. the NEC recognizes this. Also remember the ground is a normally non current path.

 

[texie]

There was an interesting article along these lines in EC&M a couple of years ago. Here is the link: http://ecmweb.com/power-quality/spinning-broadcast-web