Need Advice - Wiring Method from 200A service disconnect by meter base to 200A panel

[BAPLakebay]

Hi Everyone! I love the forum, and everyone's great insights. I'm a contractor, and here is the problem I am facing....400A/320A (continuous) New Service. By the meter base on outside wall I have two service disconnects, each feeding a separate panel inside (about 10' run). One disconnect is a Generac service rated ATS. The other is a standard 200A disconnect. There is a whole lot of conduit on this exterior wall. I want to run the feeder from the standard 200A disconnect to the panel using SER ("romex" style) feeder horizontally through the 2x6 wall studs to the panel. Can I use SER or any other flexible feeder and avoid conduit?

 

[augie47]

What type of building (occupancy ? )

 

[BAPLakebay]

Residential.

 

[jaggedben]

There's no NEC rule against using SER. That's pretty much what they make it for. Can't say from here if it's practical in your case. For example it'd be hard to bend to 90 degrees within a 5.5" wall cavity. Also there may be restrictions on the size and locations of holes you can drill through the studs, in job specs or other codes. But there's no rule against it per se. Same with FMC.