grounding electrode

[hhsting]

Attached sketch shows underground water pipes come up in building from under ground. One line sketch shows how the underground water pipes are interconnected underground.

Panel X has grounding electrode conductor going to each of the underground water pipes.

I am not sure if the water pipes are electrically continuous each other or not.

I had some variation of this post in past but that only left me more confused

Question:

1. The shaded part in one line assume its Not electrically continuous and 10 feet or more in ground. Would each water pipe require connection from Panel X or not?

2. The shaded part in one line assume it IS electrically continuous and 10 feet or more in ground. Would each water pipe require connection from Panel X or not?

 

[LarryFine]

Start with the understanding that the bonding requirement is for the electrical service, not the water service.

In other words, Panel X requires only one connection to a qualifying electrode(s).

You might need to ascertain whether all of the piping is continuous among the individual spaces.

 

[hhsting]

Start with the understanding that the bonding requirement is for the electrical service, not the water service.

In other words, Panel X requires only one connection to a qualifying electrode(s).

You might need to ascertain whether all of the piping is continuous among the individual spaces.

Lets say they are not electrically continuous between spaces then one GEC require or multiple?

Lets say they Are electrically continuous between spaces then one GEC require or multiple?


Sent from my iPhone using Tapatalk

 

[LarryFine]

Lets say they are not electrically continuous between spaces then one GEC require or multiple?

One, but you might need jumpers from unit to unit.

Lets say they Are electrically continuous between spaces then one GEC require or multiple?

One.

 

[augie47]

Is there just the one panel or does each building have a sub-panel ?

 

[hhsting]

Is there just the one panel or does each building have a sub-panel ?

Panel X feeds two meter stacks one to the right Bldg#3 and second meter stack to the left bldg #2 electrical room. The meter stacks then feed subpanels within building. There are no electrical rooms bldg#1, #4 to #6. The entire thing is apartment complex 3 stories and subpanels are in each dwelling unit. Panel X is fed from one outside feeder requiring grounding electrode system.

 

[augie47]

As Larry says, as far as a grounding electrode, one properly sized conductor from your service panel to the water line (with the 1st 5 ft).
IF the piping is continuous that's all you need to do.
IF the piping is not electrically continuous (metallic throughout) 250.104 will allow you to bond isolated metallic piping systems in each occupancy from that occupancy sub panel.,

 

[hhsting]

As Larry says, as far as a grounding electrode, one properly sized conductor from your service panel to the water line (with the 1st 5 ft).
IF the piping is continuous that's all you need to do.
IF the piping is not electrically continuous (metallic throughout) 250.104 will allow you to bond isolated metallic piping systems in each occupancy from that occupancy sub panel.,

But I don’t see what subpanels has to do with anything. In each building once water pipe enter that building water pipe is continuous. Also their are many subpanels in each building Bldg#1 etc and meterstack is not subpanel. Has no main

However the scenario is between buildings if its not electrically continuous and provide one GEC from Panel X. So lets say GEC is connected from Panel X to Bldg #2 water pipe. However between bldg #2 and bldg #1 underground water is not electrically continuous or between bldg #2 and bldg#3 underground water pipe is not electrically continuous.

The question is between buildings if underground water pipe is not continuous then which NEC 2014 section says to provide bonding jumper? NEC 2024 section 250.52(A)(1) or some other section?

 

[petersonra]

The grounding electrode conductor only goes to water pipes that are underground for at least 10 ft.

 

[hhsting]

The grounding electrode conductor only goes to water pipes that are underground for at least 10 ft.

Between bldgs it does go underground 10 feet or more please see post #1 attachment. If its not electrically connected between bldgs then not all electrodes are bonded. Which section says to provide bonding jumper in that scenario? 250.52(a)(1)?

 

[augie47]

Does each building have 10ft or more of water line direct buried with non-metallic sections of pipe between the sections ?? (so there is no electrical continuity between the piping in building 1 and building 2)

 

[hhsting]

Does each building have 10ft or more of water line direct buried with non-metallic sections of pipe between the sections ?? (so there is no electrical continuity between the piping in building 1 and building 2)

Yes each bldg have 10 feet or more direct contact with earth water line and no electrical continuity in between

I would imagine bonding jumper between the underground water pipe electrodes would be allowed if not electrical continuous by following:

250.52(a)(1):
A metal underground water pipe in direct contact with the earth for 3.0 m (10 ft) or more (including any metal well casing bonded to the pipe) and electrically continuous (or made electrically continuous by bonding around insulating joints or insulating pipe) to the points of connection of the grounding electrode conductor and the bonding conductor(s) or jumper(s), if installed.

 

[augie47]

Likely an AHJ call since they all qualify as electrodes but as Larry pointed out in Post#2 the GEC from the service panel provides grounding for the service.
With that in mind, I would allow 250.104(A)(2)

 

[hhsting]

Likely an AHJ call since they all qualify as electrodes but as Larry pointed out in Post#2 the GEC from the service panel provides grounding for the service.
With that in mind, I would allow 250.104(A)(2)

Panel X supplies the entire building and is fed from outside feeder and so require GES per NEC 2014 section 225.

So what you are saying is to do something like shown in attached sketch?

 

[augie47]

Looks lie waht Larry stated in Post #4 Go for it !

 

[hhsting]

Looks lie waht Larry stated in Post #4 Go for it !

Right but what code section would allow post #14 attachment?

I am thinking 250.52(a)(1) following part:

“...and electrically continuous (or made electrically continuous by bonding around insulating joints or insulating pipe) to the points of connection of the grounding electrode conductor and the bonding conductor(s) or jumper(s), if installed”

If not then which NEC 2014 section?