arc_flashed
Member
- Location
- FL, United States
I am looking for some help with fill/ampacity adjustment for an installation in an electrical vault. We have a trench (not sure if thats the proper term) cut into the concrete pad that all of the gear is sitting on (MCC, VFD enclosures). The plan was for all the cables including the main MCC feed to be ran in this trench. My question is does this fall under article 390 as an underfloor raceway? If so the derating for the cables would make it not practical to use this as an installation method (we would have something like 8 3/c cables and 9 single conductors crossing at one section).
Does an installation like this have a different classification that would allow for running these cables together?
If I put the different circuits in individual conduits in the trench does that qualify as individual raceways (so no ampacity adjustment)? It seems like doing this would still have heating issues as all the conduits would still be in the same raceway/trench.
Thanks in advance for your help.
Does an installation like this have a different classification that would allow for running these cables together?
If I put the different circuits in individual conduits in the trench does that qualify as individual raceways (so no ampacity adjustment)? It seems like doing this would still have heating issues as all the conduits would still be in the same raceway/trench.
Thanks in advance for your help.