Grounding Computer Rooms

[frank_n]

I have to ground the computer racks in 6 different computer rooms. I've read 645.15 which requires that the racks to be grounded per Article 250.

The racks are powered by dedicated 20 amp circuits. According to Table 250.122 I should use #12 copper. (The manufacturer calls for #10).

What I cannot find is where to connect the grounding conductor to. Should I connect it to the service? It is hundreds of feet away. Can I connect to building steel? Can I connect to a sub-panel? a water pipe? I cannot find it in the NEC.

Any advise?

Frank

 

[A/A Fuel GTX]

Use the grounding conductor that is run with your branch circuits as referenced in 250.118.

 

[raider1]

First off do the computer rooms comply with Article 645? Article 645 is not a mandatory Article, if you want to take advantage of some of the lesser wiring requirements located in 645 you must comply with ALL of that Article.

Second 250.110 already requires that fixed in place equipment that is likely to become energized must be connected to an equipment grounding conductor.

The racks are powered by dedicated 20 amp circuits. According to Table 250.122 I should use #12 copper. (The manufacturer calls for #10).

The racks just need to be connected to the EGC of the circuits feeding the equipment installed on the racks.

Chris