Switched conductors in conduit with primary?

[Chev]

I'm trying to find if there are any prohibitions against this:
3 phase 480 volt feed to a fused switchbox, the same conduit also being used to route the secondaries? The feed is coming through a trough, going back out through the same trough.
Somewhere in the back of my head it is telling me that this is a no-no...any help out there

 

[nakulak]

is the feed a service, or unfused ?

 

[Chev]

It is a feed from a 480 volt bus. We are updating wiring methods to escape weld plug disconnects due to OSHA and the love of conduit v/s cord for machine power distribution. So the feed comes off the 480 v bus fused at 200 amps, comes to a trough, is spliced to downsize the conductors, then goes to a FUSED disconnect via a conduit nipple. Currently the wires coming off the fuses (30-60 amp) are being routed through the same nipple as the feed to/from the trough, where they then go out to the machine they feed. And no, there has not been any direct supervision by any management or engineering personnel, I'm out here on a limb :roll:

 

[Mulrooney]

I think what you are calling secondaries are actually the same conductors thqat feed the disco, only they are on the load side of the disco, right? If so there is nothing wrong with that.
What I think may be wrong is your down sizing of conductors once you enter the trough. 200 amp overcurrent protection at the buss to 30/60 amp overcurrent protection at the disco's sends up a red flag about tap rules.
are you connecting smaller conductors (say 10's or 6's) to larger conductors from the buss in the trough and then going to the discos?

 

[Chev]

Ya, the "line side" is coming off of a 100 amp bus plug (I went out and rechecked) which feeds the trough where the wire is spliced to feed (4) 60 amp disconnects that are fused.The disconnects are fused at 60 amps, the panels they feed are less. Needless to say the potential load would be smoking fuses in the bus plug, but not all machines are runnning at the same time. It is in 1 section of a small machine shop. So that kills the tap size question as they ran #2 and tapped with #6. Something is just saying the primaries and secondaries shouldn't be in the same conduit...maybe it's in machine tool standards...