Use of same conduit for feeders

[spector2]

Is there an artlicle in the NEC that prohibits a single conduit from being used to route the feeder conductors from a PV solar inverter to the AC disconnect and back to a junction box before routing to the commercial electrical meter service panel for connection?

 

[iwire]

Not exactly prohibited but the derating rules usually make such moves with feeders to be a bad choice.