An existing 600A disconnect with parallel 350MCM per phase in 3-1/2" conduits that leaves the bottom of the disconnect and goes underground immediately. The disconnect is surrounded by other service equipment (multiple services) and there is not much room.
An ASCO automatic transfer switch was added to this feeder. The contractor mounted the switch nearby on a new concrete pad. To get from the disconnect to the ASCO switch and back the contractor installed 8" wireway and 3-1/2" conduits. That part looks fine. Inside the disconnect however you have parallel 350MCM leaving the load side of the disconnect going out the side of the disconnect through 2- 3-1/2" chases then you also have the same parallel 350MCM's coming back from the ASCO switch through 2 more 3-1/2" chases. Then splices were made to the underground feeder in the disconnect. So in the disconnect you have a big pile of splices and wire, but it is the same feeder, not a foreign one. Burndy Unitaps were used which helped on space but the disconnect is crowded.
Outage time was a concern, I think, since the service is for a call center type business.
Not sure there was another way to do it without huge expense (i.e. digging up half the parking lot and rerouting conduits).
I doubt you have a code violation, it would have to exceed 75% fill (darn near imposable to do) at the splices to be a violation.
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.
Bob Badger Construction & Maintenance Electrician Massachusetts
#95715 - 10/07/0510:31 AMRe: Code Violation? Splices in Disconnect
I'm not sure I fully follow the routing but had this been required emergency power rather than the optional standby power for a call center would using the same trough for the supply and emergency conductors violate the code? Would allowing the normal supply conductors to enter the disconnect before being routed to the transfer switch be a problem?
I'm thinking here of the language in 700.9.
700.9 Wiring, Emergency System.
(B) Wiring. Wiring of two or more emergency circuits supplied from the same source shall be permitted in the same raceway, cable, box, or cabinet. Wiring from an emergency source or emergency source distribution overcurrent protection to emergency loads shall be kept entirely independent of all other wiring and equipment, unless otherwise permitted in (1) through (4): (1) Wiring from the normal power source located in transfer equipment enclosures (2) Wiring supplied from two sources in exit or emergency luminaires (lighting fixtures) (3) Wiring from two sources in a common junction box, attached to exit or emergency luminaires (lighting fixtures) (4) Wiring within a common junction box attached to unit equipment, containing only the branch circuit supplying the unit equipment and the emergency circuit supplied by the unit equipment.
Any help in understanding the application of this article using the above physical facts as the example would be appreciated. -- Tom Horne
"This alternating current stuff is just a fad. It is much too dangerous for general use" Thomas Alva Edison