G-N connections in secondary MLO panel fed from Feed-Thru Lug

[darunedefig]

I am at a job that the 200A Main service panel in garage has grounds and neutrals connected. There are feed-thru lugs at opposite end of main 200A breaker. The conductors from the feed-thru lugs are 200A rated and go to the lugs of a 200A main lug only panel that is 20' away in basement. The MLO panel has several grounds and neutrals connected together on same bar. Would we call this MLO panel a subpanel and thus the grounds and neutrals should be separated?
I guess the thinking was that the MLO panel is just a continuation of busbar of the main panel.

 

[augie47]

It would be a subpanel and require a 4 wire feed and neutral and equipment grounds separated,

 

[don_resqcapt19]

Is this all one building or two separate buildings? If two separate buildings and the original installation was under the 2005 or older code, you were permitted to just run 3 conductors and rebond the neutral at the second building. If this is the case the neutrals and EGCs can be on the same terminal bars.

 

[Knightryder12]

I would think this would just be a second section of the main, and would not require the neutrals and grounds to be separated as there was no mention of a main in the second section.

 

[texie]

I would think this would just be a second section of the main, and would not require the neutrals and grounds to be separated as there was no mention of a main in the second section.

No, the second panel is not service equipment and the conductors feeding it are feeders. The service disco. is in the first panel and that is where the main bonder jumper is. There can be no main bonding jumper in the second panel.

 

[augie47]

I would think this would just be a second section of the main, and would not require the neutrals and grounds to be separated as there was no mention of a main in the second section.

Unless it's in a separate building the second section would not necessarily need a main if protected at it's supply (408.36)

 

[darunedefig]

Is this all one building or two separate buildings? If two separate buildings and the original installation was under the 2005 or older code, you were permitted to just run 3 conductors and rebond the neutral at the second building. If this is the case the neutrals and EGCs can be on the same terminal bars.

One building. Thanks for the extra info.

 

[ggunn]

Is this all one building or two separate buildings? If two separate buildings and the original installation was under the 2005 or older code, you were permitted to just run 3 conductors and rebond the neutral at the second building. If this is the case the neutrals and EGCs can be on the same terminal bars.

But as you say, it would be a three wire run (no grounding conductor) between the buildings. If there is a ground wire to the second panel it cannot be bonded to neutral in the second panel.

 

[infinity]

One building. Thanks for the extra info.
I guess the thinking was that the MLO panel is just a continuation of busbar of the main panel.

Then a feeder containing both an EGC and neutral would be required but you do bring up an interesting point about the feed-thru lugs.