Use main panel to pass through a second set of service wires?

[Stuntman]

I have a dual lug meter which I would like to pass the first set of service wires through a short (<<24") 3" nipple to the first main panel.

The second set of service wires, I would like to put through this same 3" nipple (NEC Fill is OK), then simply pass them through this first main panel box to another nipple exiting the back of the panel and feeding a second main disconnect.

In short, can I use the area of the first main panel as a pass-through box for a second set of service wires.

This would greatly clean up a new service where both main panels are in close proximity to the meter, one inside of a wall, the other on the outside of the wall.

 

[wwhitney]

Panel enclosures may contain service conductors, including those not terminated within that panel enclosure. Any conduit (like the 3" nipple you mention) that contains service conductors may not contain non-service conductors.

So if I understand the configuration you are describing, it is compliance with 230.7. But you mention exiting the back of the first panel to get to the second panel. Will your configuration comply with the grouping requirements in 230.72? You can't have one service disconnect inside the building and one outside the building.

Cheers, Wayne

 

[Stuntman]

wwhitney - Thanks for the feedback:

1. The nipples will be much less than 24" long (no derating)
2. The nipples will ONLY contain service wires (2 sets) and no non-service conductors.
3. The main panel for the building power is on the inside of the building while the disconnect on the outside is for a separate building (60ft away). The local power company requires an emergency disconnect before the feeder wire goes underground, I am used a second main panel as that disconnect.

 

[Stuntman]

wwhitney, I take it you don't see a code violation?

I have to punch my own hole in the back of both disconnect panel boxes to allow me to feed from the back, I have never done this for service wires. Do I need to worry about bend radius of the service conductors in this instance?

 

[wwhitney]

wwhitney, I take it you don't see a code violation?

Correct.

I have to punch my own hole in the back of both disconnect panel boxes to allow me to feed from the back, I have never done this for service wires. Do I need to worry about bend radius of the service conductors in this instance?

NEC 312.6 covers this. The only way I see that you could have a problem is if the terminal only has wiring space sized per Table 312.6(A), Conductors Not Entering or Leaving Opposite Wall, and your new hole would be in the opposite wall of the terminal, so that the larger values Table 312.6(B) would now apply.

Cheers, Wayne

 

[augie47]

In our jurisdiction you would not be required to have a disconnect at the meter for the conductors to the separate building and if you did install one the 2 disconnects would have to be grouped

 

[wwhitney]

In our jurisdiction you would not be required to have a disconnect at the meter for the conductors to the separate building and if you did install one the 2 disconnects would have to be grouped

Hmm, I guess this comes down to 230.40? If the two sets of SECs from the meter are installed under 230.40 Exception 2, then that exception requires grouping of the disconnects. While if this happens to be a single family dwelling and an accessory building, 230.40 Exception 3 does not have any language requiring grouping.

Cheers, Wayne

 

[augie47]

Our inspection dept and POCO have no problem with 230.43 Exception 3 as there would not be a disconnect for the detached structure at the main structure.
Their logic is a disconnect at the meter will be construed as the disconnect for that building