Bonding multiple panels

[Dansos]

Hey guys I’m sorry for asking this as I know it’s been covered here before, but I can’t find a thread anywhere about this specific instance.
We installed a 600A resi service recently that was set up as follows:

500AL x 2 running into blocks inside an exterior gutter.
From the blocks we are feeding (1) 320A meter and (2) 100A meters (All single phase)

Inside the house we have (2) 200A Main Breaker panels and (2) 100A Main breaker disconnects.
My question (confusion) revolves around the grounding of the system and how we are supposed to properly bond the enclosures in the building.

We ran #6Cu to (2) ground rods and landed it inside panel 1. Then we just jumped from 1 to 2 to 3 to 4.

Now when we are going to be grounding the system via a water pipe, I used Table 250.102(c) and got 250AL as a proper size to run to the water pipe.

So, does the 250AL need to be landed in panel A and then jump to the other panels just like our #6 did?

I think, from reading the codes, that it DOES need to be connected to all the panels inside the house. 100A disco’s have literally NO space inside to put a 250 lug, let alone 2, so I then thought of just running 1 into each panel and landing them all inside a tap connector on top of the panels. Is this something that sounds cool???

PS: Gutter above meters is bonded with 250AL as well and ran inside to where the panels are.

Please just help guide me into the thought process of figuring out how to correctly size this and how to properly bond these panels together.

thank you in advance!!!

 

[texie]

I'll try to be gentle but what you are describing has so many code issues I'm not sure where to start.

 

[SSDriver]

This should help out on sizing. But it does sound like you have many issues with location of meters/disconnects etc.

 

[Dansos]

I'll try to be gentle but what you are describing has so many code issues I'm not sure where to start.

I’m sorry maybe I did not word things correctly, or explained them wrong. I don’t think anything I explained in terms of the layout of equipment is a code violation.

 

[Dansos]

This should help out on sizing. But it does sound like you have many issues with location of meters/disconnects etc.

View attachment 2556133

Thanks for the drawing. The statement “based on the largest ungrounded conductor from each disconnect” is what sorta confuses me. To me, that sounds like I size the GEC off the wires coming INTO the disconnect and NOT the service entry wires.

 

[infinity]

You can run the GEC (Table 250.66) from the water pipe based on the size of the SEC's and then tap off to each panel with a bonding jumper based on the size of the conductors feeding each individual disconnect. The taps can be connected with split bolts. You would not jump from panel to panel.

 

[Dansos]

You can run the GEC (Table 250.66) from the water pipe based on the size of the SEC's and then tap off to each panel with a bonding jumper based on the size of the conductors feeding each individual disconnect. The taps can be connected with split bolts. You would not jump from panel to panel.

View attachment 2556134

Thank you for the explanation. So if we were to run the GEC to a point and then just tap off each panel and connect them all to the GEC that would suffice ? I think I get it now lol.

 

[infinity]

Thank you for the explanation. So if we were to run the GEC to a point and then just tap off each panel and connect them all to the GEC that would suffice ? I think I get it now lol.

Yes that is permitted.

 

[Dansos]

I'll try to be gentle but what you are describing has so many code issues I'm not sure where to start.

Maybe it’s me, but this type of comment is the exact reason why many people don’t post questions on here. It’s pointless to say this without giving a code citation of WHY it’s a violation. Don’t be gentle with me. When I bid a job and screw something up it costs me $$$$$$..... I ask these questions bc I want to understand and learn things and not look like an idiot when an inspector comes.