This is the most quoted rule



... and it comes down to "unless adequate space for this purpose is provided".

This is generally a "I can't define it but I know it when I see it" sort of thing.

Is providing sufficient air gap between the wires and the buss adequate?

Would moving the 2.5" conduit forward by 3 or 4 inches be a suitable solution?

1st off, that red piece looks introduced, so methinks the adequate room ,if not "workmanlike" defintion might gain some legs on that alone

2nd, i'm not finding anything more than 3-500's in table C1

3rd, 500 cu per 310.15(b)(16) is good for 380A

10 lashes for the apprentice i say!

~S~

As the conductor fill in the 2-1/2" conduit is in violation; correction of that has to be made. So, while increasing the conduit size, I would relocate it to the adjacent distro panelboard.

Is this gear a 'service'??

As observed from the pics, it appears that the conductors are within the barriered area (line side) of the main gear section.
This can be a POCO issue, IF the CTs are within the 'barriered section'. This could also be a violation for failing to follow mfg instructions.

The bussing runs N - Top; then A,B,C - top down.

All of the Siemens 'big-boxes' I've installed (EUSERC) had a dedicated U/G pull section that took the bussing up high -- which feed a MAINS box -- with the current flowing from the Top down into the MAIN breaker -- thence off to bussing that exited low going to the various Distribution Boards.

These featured vertical bussing and 3 phase breakers mounted very much in the SqD I-Line style.

Your box appears to have a bottom to top current flow in the MAIN.

This would fail EUSERC standards.

Also, EUSERC would never permit your line side penetrations -- regardless of any other factor. It's space deeded over to the Poco -- and they don't want ANY customer circuits in their domain.

Where I come from the PM and Foreman would be pulled off the job/fired and the entire scheme re-worked.

BTW, on the load side, the bonding bushings make no sense.

The bonding conductor is improperly un-labled: it need be bare or banded green - -black doesn't cut it.

I see no provision for CT's or meters.

Is this, in fact, a sub-panel -- taking its power from a yet more powerful Distribution Board?

If this is the case, then the Poco is out of the picture, and you can get away with just re-routing the conductors -- per Code.

I still can't figure out how you're able to get away with reverse flowing the MAIN. That's a straight up Code violation -- right there.

Tesla:

Yes, a 'pull section' is common here also, along with line-top; load-bottom on CBs. However, a CB could be line-bottom, from the mfg.

Noting the barriers on the lower section of the main, I believe that is the 'line' side.

No provisions for CTs? I have come accross some that use 'donut' CTs out in the pad mount xfr, along with the meter at the xfr location. Not common, but I have seen it.

This also may be downstream from the MSB. Pehaps the OP could shed some more details on this.

Nothing wrong with that. Why did you post it as though it's a violation?

See 240.4(B)

Why would a rooftop unit of that size require a neutral? Seems odd to me, units of that size should have integral control power transformers. Though I guess there could be 277V motors in it, seems unlikely.

Is the conduit used as the grounding conductor?
I've always found it better practice just to run a seperate conductor out there, especially with loads of this size.