Hello,

I'm replacing my main panel with a 100 amp breaker alone ( disconnecting means ) and running out of their to my sub panel,
30 feet away which will supply all the circuits, reason: location wasn't a good place, but needed within 6'
From outside meter, so I decided to make a sub panel that supplys the house circuits.

Above the sub panel, I want to put a trough or junction box to bring all the
Romex's into the closure and then pipe down to the sub panel. My problem is sizing the pipe from
The trough to the sub panel and sizing the trough. I've been searching the code book and still not
Sure on what I should do, I don't need it inspected, cause I haven't changed the amp size of the panel
And kept it 100 Amp panel. I have a 24 slot circuit panel, 2 which are 30 amps, 2 are 20 amps and the
Rest are 15 amp breakers, I'm rewiring the house with 2-12 w/ground wire conductors besides the 30 amp
Breakers which are 2-10 w/ground conductors.


2-#10 wire romex - 2 cables, total wires = 6 Total wires with grounds.
2-#12 wire romex - 22 cables, total wires = 66 Total wires with grounds.

72 Total wires, 6 of them are #10's wire size

My idea to minimize the size of conduit would to put a ground bar in the trough and run an #8 ground in the conduit to the sub-panel,
So my new total would be: 51 Total wires.

So my question would be, What size conduit would I need from the Tough to the Sub-Panel and what size Trough will I need?

You really need to re-think this idea. You have the wrong idea to begin with,

The main panelboar or cut off switch must be at the "Closest" point to the service entry, not within 5'.

The 5' requirement is for connecting your Ground to the cold water pipe. That connection must be made within 5' of the metal pipe's entry into the building.

If you are making this change for purley cosmethic reasons, then do not do it! Also, if the trough is going to be greater than 24 inches, then you must do adjustments for both cable fill and heat.