racks that hold servers & communications boxes

[boatfull]

Do the metal racks that hold servers and other communication boxes require that the frame be bonded? These racks are usually in the IT room.

 

[tryinghard]

I think so, see 250.96(A) & 250.4(A)(4)

 

[stevebea]

Do the metal racks that hold servers and other communication boxes require that the frame be bonded? These racks are usually in the IT room.

If the rack has AC powered equipment installed in it that is electrially bonded to the frame and the circuit feeding the rack has a properly sized EGC there is no further requirement according to the NEC.

 

[hbiss]

If the rack has AC powered equipment installed in it that is electrially bonded to the frame and the circuit feeding the rack has a properly sized EGC there is no further requirement according to the NEC.

That is correct. Matter of fact you don't want to bond a rack full of equipment or you could be setting yourself up for some nasty ground loops.

-Hal

 

[esobocinski]

In a closet installation I would agree with you. However, a real data center of any significant size will have a separate bonding system for all racks that connects at a single point to the equipment ground system. Without it, the data center can develop troublesome potential differences from one end to the other.

 

[ceb58]

In a closet installation I would agree with you. However, a real data center of any significant size will have a separate bonding system for all racks that connects at a single point to the equipment ground system. Without it, the data center can develop troublesome potential differences from one end to the other.

Agreed, in our communication buildings the racks are bonded to a grounding halo that is a single point grounding system. All required by Motorola's R-56 grounding standards.