Ethernet surge suppressors

[Eug]

This typically is not code and can be considered dangerous. Structure should have either 1 ground point or multiple that are all grounded together (dedicated ground wire 'structure' doesn't count.)

NEC 250.50:

NEC 250.50 All grounding electrodes that are present at each building or structure served shall be bonded to-gether to form the grounding electrode system.

NEC 250.50 Electrodes include a metal underground water pipe in direct contact with earth for 10 feet or more, a metal frame of a building or structure, a concrete encased electrode or a ground ring.

NEC 250.66 The size of the grounding electrode conductor shall be determined by the size of the service-entrance conductors, per the chart:

Equivalent Size of Service Entrance Conductor 	Size of Grounding Electrode Conductor
Copper		Aluminum			Copper
4 AWG		2				8*
1 AWG		2/0				6
2/0 or 3/0	4/0 or 250			4

There is a ton more but I don't feel like typing all of 250.50 out as it is rather long. The key thing about pipe grounding is that the ground point is actually the ground for the piping system and not technically a structure ground. They also forbid using the pipe itself as a multiple ground point for reasons stated above.

The framing of the addition where the Ethernet comes in is metal. I'm still gonna ground to the metal electrical gang box, but just for future reference, does this mean under that code it is not recommended to ground to the metal framing if the ground is the pipe?

Cuz if the electrical boxes are all fastened to the metal framing wouldn't that mean it's all electrically bonded anyway?

 

[imagoon]

The framing of the addition where the Ethernet comes in is metal. I'm still gonna ground to the metal electrical gang box, but just for future reference, does this mean under that code it is not recommended to ground to the metal framing if the ground is the pipe?

Cuz if the electrical boxes are all fastened to the metal framing wouldn't that mean it's all electrically bonded anyway?

Older houses used to use the water pipes as a ground because they are all metal and are typically at least 10 feet long. What they recommend now is to have a copper rod buried and the pipes grounded via typically a 4 gauge wire. You are not supposed to ground it at multiple points however. IE You are not supposed to ground say, a couple of outlets on the opposite side of the house to the pipe. Basically don't use pipe as a bus bar.

 

[Modelworks]

Keep in mind that your local building code is probably different then mine. And, sometimes you do what you have to do.

I have seen people pour a cement slab over the main ground rod. Making it impossible for phone of cable tv to be grounded at the same location.

Power going into the house from one side, phone on the other side.

In a perfect world everything would be bounded/grounded at one central point. But we dont live in a perfect world do we.

Local codes for electric wiring are almost gone in the USA, most states have adopted 2008 rules and some already are 2011. The NEC codes are minimum requirements. Local codes add to the rules but do not remove them. Pouring cement over a ground rod isn't compliant and never has been. If a home has a grounding related damage claim, insurance companies can and have refused to pay.

 

[Modelworks]

The framing of the addition where the Ethernet comes in is metal. I'm still gonna ground to the metal electrical gang box, but just for future reference, does this mean under that code it is not recommended to ground to the metal framing if the ground is the pipe?

Cuz if the electrical boxes are all fastened to the metal framing wouldn't that mean it's all electrically bonded anyway?

It depends on the metal framing. There is a section of code that addresses grounding of metal structures.

Structural Metal. Where exposed structural metal that
is interconnected to form the building frame exists in the
area served by the separately derived system, it shall be
bonded to the grounded conductor of each separately de-
rived system. This connection shall be made at the same
point on the separately derived system where the grounding
electrode conductor is connected. Each bonding jumper
shall be sized in accordance with Table 250.66 based on
the largest ungrounded conductor of the separately de-
rived system.

Basically the building is supposed to grounded to the same ground point the wiring of the building is using by way of a ground bonding jumper. That makes the building the same potential as the ground rod and you will not get ground loops when you attach an outlet box that is metal and grounded to the building.

You could attach a short wire near the ground rod to the metal frame and that would satisfy the requirements.

 

[imagoon]

It depends on the metal framing. There is a section of code that addresses grounding of metal structures.



Basically the building is supposed to grounded to the same ground point the wiring of the building is using by way of a ground bonding jumper. That makes the building the same potential as the ground rod and you will not get ground loops when you attach an outlet box that is metal and grounded to the building.

You could attach a short wire near the ground rod to the metal frame and that would satisfy the requirements.

Even with all that they still tell you to run ground wire in the conduit and use that. (in circuit grounds in conduit only need to be normal 10 or 12 gauge. The reason is the metal structure cannot be assumed to be a "perfect" ground after a few year. Ie something bolted together might not be electrically sound 10 years later.

The general rule of thumb is: "can it be electrically energized?" If yes: Should it be? if no: Inter-ground it all and tie it all down at the main ground. The idea being if you short a hot phase to a metal wall, it will trip the breaker via the ground paths so someone doesn't die.

This is why you will see metal structures with wire jumpers going from panel to panel. They consider it "2 systems."