Grounding Ring

[john2016]

I'm working in a building where there are 10 floors. Each floor has it's own electrical room with a grounding ring in each room that grounds 6 panels within the room. The grounding ring is then connected through each floor and then grounds at the main electrical service on the first floor.

My question is the existing grounding ring properly grounded the way it is connected in these pictures? The panels are mounted on the unistruts and the ground wire is secured to the unistrut. The ground wire is always touching the metal ventilation grill.

 

[infinity]

Connections are irreversible which is correct. IMO the only possible issue in the photo's is the corrosion in photo #3. Although it encircles the room it's not an Article 250 ground ring.

 

[augie47]

Be interesting to know the reasoning behind the install especially considering the duct work.
The panels appear to have EMT feeders so they would be grounded to Code without the addition.
If there are transformers in the rooms the install would make more sense due to 250.30(A)(6)

 

[john2016]

Thanks for your response. Would matter if the bare #4/0 ground wire is touching the metal ventilation grill and conduit?

 

[john2016]

The rooms were set up as what is shown on the attached detail. This was done back in 1984 and yes there are transformers above the panels in the room.

 

[infinity]

Thanks for your response. Would matter if the bare #4/0 ground wire is touching the metal ventilation grill and conduit?

I see no reason for it to isolated. I don't think that there's anything in the NEC that saying it cannot be in contact with other metal.

 

[augie47]

I see "patient ground module" on the prints. Is this or was this a medical facility ?

 

[john2016]

Yes. It's a hospital.