is it possible not to provide ground wire between panels

[victor.cherkashi]

is it possible not to provide ground wire between panels and instead connect ground bus-bar of panel to a building steel construction. (the tenant panel on 5th floor and energized from base building panel in corridor, see attached pictures).

 

[jumper]

I cannot see your pics, however if you are asking if you may use the building steel as the EGC of a feeder between panels then the answer is no.

Approved EGCs are listed in 250.118.

 

[charlie b]

You second picture shows a connection to building steel not from the ground bar, but for an isolated ground. Not only will that violate code, it would not serve the purpose for which isolated grounds are permitted. Why would you want to avoid bringing a wire-type EGC (and if needed, a wire-type IG) to the new panel?

 

[victor.cherkashi]

Thank for the answers.
It's not my design.
1. probably 2" conduit between panels services as EGC of the feeder.
2. connection to the building steel does not make much sense for me. If I would do it, I would take the ground wire to a main ground bus in basement if I wanted to reduce noises for electrical equipment.


Does it make sense to take ground wire from basement for isolated ground bus bar in panel?

 

[infinity]

is it possible not to provide ground wire between panels and instead connect ground bus-bar of panel to a building steel construction. (the tenant panel on 5th floor and energized from base building panel in corridor, see attached pictures).

If you're using a metallic raceway between the panels such as EMT that can serve as the EGC for the feeder. Looks like they want an IG system, any idea why? These systems are basically obsolete.

 

[victor.cherkashi]

IG is for two receptacles in IT closet.
Why is IG system obsolete?

 

[dkidd]

Does it make sense to take ground wire from basement for isolated ground bus bar in panel?

Absolutely.