First Post Grounding Question - 320A Meter Pedestal to Two 200A Panels

[cmwilson7]

Hi,

This is my first post....

I am an electrical engineer and do predominantly substation protective relay work where I rarely reference the NEC but I have a need to install a temporary construction service that will need to meet code and I have a question about the grounding requirements that I am trying to get right for the contractor doing the work.
The service is in Wisconsin and is a 320A service (how it is referred to by the supplying utility) where I will be using the utility approved Eaton 1009017CH meter pedestal which itself contains two 200A breakers. I will leave the meter pedestal with two sets of (3) 3/0 conductors to each of the two 30 pole 225A rated panelboards with main lugs only. All of this will be installed on to a two post / cross strut frame.

For the grounding, I plan to have two 8' x 5/8" ground rods 6' apart with #6 CU routed as one continuous conductor from the farthest ground rod to the grounding lug on the neutral bar in the meter pedestal. In the two 225A panelboards, I have the neutral and ground bars separated since the neutral and ground bonding is done in the meter pedestal. The neutral bar in the panelboard has a 3/0 neutral connection to the meter pedestal. The ground bar has a #6 insulated equipment grounding conductor connected to the neutral bar ground lug in the meter pedestal. Conduit b/w the meter pedestal and the panelboards will be PVC but might have pvc coated metalic hubs, not sure what is normally done there or if the hubs are required to be grounded even if you have non-conductive conduit.

Questions:
1. Do you see anything wrong with my planned installation?
2. Do I need to connect one of the galvanized posts to the #6 GEC as it routes from the ground rod to the meter pedestal or is this covered by the panels being mounted to the frame?
3. Is there a need for anything larger than the #6 GEC in this case? Or, if I do connect the GEC to the galvanized frame post, do I then need 1/0 to meet code (sized for dual 3/0)?
4. Are the #6 equipment grounding conductors sized correctly? I did #6 here per Table 250.122

Thanks!

 

[petersonra]

I think you will need a SSBJ.

 

[augie47]

What NEC Code cycle is in effect ?

 

[electrofelon]

I think you will need a SSBJ.

Sounds like just a MBJ in the meter (which is certainly already factory installed) is all that is needed.

What NEC Code cycle is in effect ?

Whatcha thinking augie as to why that would matter?

It all sounds fine to me. Just the two rods is all that is needed, the posts likely don't meet the requirement to be a grounding electrode, and I say the whole frame is bonded by being bolted to the strut, the panels and the meter socket.

 

[cmwilson7]

What NEC Code cycle is in effect ?

2017

 

[augie47]

2017

(Later Codes might make you meter/main an issue)
I see no issues

 

[tom baker]

An electrical contractor can easily do this. Just write in bid specs comply with currently adopted NEC/local codes, and require a permit/inspection

 

[cmwilson7]

An electrical contractor can easily do this. Just write in bid specs comply with currently adopted NEC/local codes, and require a permit/inspection

I figure as much but they asked for something on paper and I want to make sure what I am putting down meets code. For the work that I do on a day to day basis inside of a substation, I rarely touch the code book but am interested in becoming more proficient with it.

 

[tom baker]

I figure as much but they asked for something on paper and I want to make sure what I am putting down meets code. For the work that I do on a day to day basis inside of a substation, I rarely touch the code book but am interested in becoming more proficient with it.

That is a great reason