When doing a new construction project, exactly what should you tell the electrician to provide so that you can properly ground your rack?

This has been discussed on this forum, and I've done a bunch of Google searches, but I still don't have a clear sense. Sorry if I'm being daft.

In commercial data installations the electrical contractor will typically provide a telecom grounding busbar in the datacom closet. That TGB is bonded to the primary bonding point/bussbar for the building. TIA-607-C covers this.

That’s good info, thanks.

Is it accurate to say that proper grounding / binding is necessary for these separate purposes:

1. Shock hazard mitigation
2. Noise / ground loop reduction
3. Surge protection

This is a good reference document

[Link: middleatlantic.com]

I realize that I didn't ask the question right. Really, I am trying to understand the entirety of the grounding infrastructure that should be provided by an electrician.

For example, I have been trying to understand the correct way to provide grounding and surge protection for LV cabling that comes in from the outdoors, whether from service providers or from devices located outdoors (i.e speakers, cameras, WAPs, pool controllers, etc.)

As I understand it, there should be some ground attachment point anywhere such cables enter the building. So, if telecom service enters at point A, speaker cabling enters at point B and pool control cabling enters at point C, you really need some sort of grounding bar at all three location. And, this is all in addition to the grounding bar that should be provided at the equipment rack. Correct?

The electrical contractor should know the NEC- ask if they're familiar with LV grounding articles and base your next steps from their answer. The NEC has a whole section on grounding and bonding communication equipment and electric service. Make note that bonding and grounding are related, but not the same.

The electrician only needs to provide a point of grounding. This can be as simple as bare copper for the house grounding system OR as advanced as a grounding buss bar (not typical in residential). It is now up to you to ensure your wiring and devices are connected to this system. This is as simple as plugging a unit into the wall (3 prong devices are grounded) or using appropriate connectors to connect a device to the provided ground.

It is recommended that you bond/ground any incoming wiring as close to the entry point as possible but most times this isn't possible so placing the bonding/grounding termination at the rack is the only option.

Within a rack this is as simple as running a #8 insulated copper wire (#6 if bare copper) from the rack bonding lug (that bottom lug most people ignore) to the provided grounding point. Then using #12/14 insulated copper from each device to the bonding lug. MA also makes a copper buss bar you can use as an alternative to the bonding lug.

EC&M has some great articles on grounding and bonding, some are behind a paywall but many are free.

[Link: ecmweb.com]

This BICSI/Panduit pdf is also helpful.
[Link: mercommbe.com]

For devices not wired to the rack, they also would need an insulated 8 AWG copper conductor, from the cable entrance to the resi main grounding busbar (or whatever is used at the service entrance, e.g. Intersystem Bonding Termination)?



[Link: ecmweb.com]

Is this IBT widely used for new resi construction?

This is good info. The BICSI/Panduit pdf refers to TIA-607-B, with this simple directive (echoed by others on this board):

“Rather than relying on the ac power cord ground wire, it is desirable that equipment be grounded in a verifiable manner as described in this Standard.”

It then goes on to describe the topology and sizing of the grounding wires for achieving that desired manner.

I believe it is required by the NEC now for new construction.

Is "point of grounding" the thing that goes into the ground, say, a ground rod? Or is "point of grounding" the buss bar that all the "grounds" in the house are attached to (which then attaches to the ground rod)?

Reading and rereading the first paragraph, I don't see any detail that tells me whether this "point of grounding" is the house side or the earth side of the setup.

Great thread!

Ernie, sorry for not being clear.

The point of grounding (or grounding point) is the location where you are able to connect your bonding wires to the ground rod/plate. This can be either some type of ground buss bar or the copper wire. In both cases these must be properly connected using either#8 insulated copper or#6 bare copper (size increases if wanting to use aluminum) with the approved connectors (split bolt, non-reversible crimps, etc) to the ground rod or plate.

In most residential buildings in Ontario Canada the grounding point is usually a #6 bare copper ground wire from the electrical panel to the ground plate. We install a copper split bolt and connect our bonding wire/s to this.

Now it looks pretty obvious -- it's neither the part that goes into the ground nor the bunch of wires that collect to be connected to the part that goes into the ground. It's the place where one of these things connects to the other.