Can subpanel feed and branch circuits be in same conduit?

[malibu101]

Adding a subpanel next to the main panel to gain some extra breaker spaces.
Would like to run 1 conduit between the panels to take the subpanel feed wires AND the wires for 2 120V/20A single pole branch circuits through this conduit.
Is this code legal? Or must the subpanel feed and branch circuits be in separate conduits?

Conduit fill will not be a problem. Conduit will be plenty big enough.

 

[Bert_]

Absolutely OK for a feeder. If this were a service then you could not.

 

[mm08822]

There is more to it than how many conductors can fit in a conduit even with 40% fill observed.

The conductor count in the conduit will cause a derating of all conductor ampacities above 3. 4-6 =80%. 7-9 =70%. 10-20 = 50%.

Better to move the home runs from the main panel into the sub panel and completely eliminate any branch ckts from the feeder conduit.

 

[pattenp]

There is more to it than how many conductors can fit in a conduit even with 40% fill observed.

The conductor count in the conduit will cause a derating of all conductor ampacities above 3. 4-6 =80%. 7-9 =70%. 10-20 = 50%.

Better to move the home runs from the main panel into the sub panel and completely eliminate any branch ckts from the feeder conduit.

If the new panel is next to the existing panel and the connecting conduit/****** is less than 24 inches in length the fill rate can be 60% and conductor derating does not apply. See NEC Chapter 9 Table 1, Note 4.

 

[malibu101]

If the new panel is next to the existing panel and the connecting conduit/****** is less than 24 inches in length the fill rate can be 60% and conductor derating does not apply. See NEC Chapter 9 Table 1, Note 4.

The length of conduit is about 10" so it sounds good.
Thanks for the NEC section citation!

 

[mm08822]

If the new panel is next to the existing panel and the connecting conduit/****** is less than 24 inches in length the fill rate can be 60% and conductor derating does not apply. See NEC Chapter 9 Table 1, Note 4.

Not an exception I typically use b/c of the lack of need. None the less - you're right.