ATS as Wireway?

[EEhogum]

I'm working on a design to replace an existing 1600A, 208/120v, 4-pole Service Entrance Rated with circuit breakers Automatic Transfer Switch (ATS) with a new one meeting the same ratings mentioned above. The problem is lack of space where this ATS and Main Distribution Board are located. The existing ATS currently contains (2) branch feeders from the MDB that are routed through the adjacent ATS before entering their feeder conduits to their load panels. These feeders have nothing to do with the ATS.

When I replace the ATS with a new one, are there any code/warranty/listings that will be violated if the (2) feeders are again routed through the new ATS to meet up with their existing conduits?

I couldn't find anything in the code that address this issue. Any help would be greatly appreciated!

Thanks.

 

[augie47]

The only Article that I can think of that might apply is 312.8:
312.8 Enclosures for Switches or Overcurrent Devices.
Enclosures for switches or overcurrent devices shall not be used as junction boxes, auxiliary gutters, or raceways for conductors feeding through or tapping off to other switches or overcurrent devices, unless adequate space for this purpose is provided. The conductors shall not fill the wiring space at any cross section to more than 40 percent of the cross-sectional area of the space, and the conductors, splices, and taps shall not fill the wiring space at any cross section to more than 75 percent of the cross-sectional area of that space.

 

[EEhogum]

Thanks for pointing that out!

The new 2011 edition has completely revised 312.8. It now states:

"The wiring space of enclosures for switches or overcurrent devices shall be permitted for conductors feeding through, spliced, or tapping off to other enclosures, switches, or overcurrent devices where all of the following conditions are met:
(1) The total of all conductors installed at any cross section of the wiring space does not exceed 40 percent of the cross-sectional area of that space.
(2) The total area of all conductors, splices, and taps installed at any cross section of the wiring space does not exceed 75 percent of the cross-sectional area of that space.
(3) A warning label is applied to the enclosure that identifies the closest disconnecting means for any feed-through conductors."

This answers my questions. Thanks again for the help!