NM into panel thru short piece of PVC conduit

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richwaskowitz

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Shelby Twp. MI, near Detroit
I have read and believe I understand 312.5 (C) but I just want to know if I am missing anything in the proper way to run multiple home-runs into a breaker panel when the panel is surface mounted (as in mounted on the wall in an unfinished basement) through a short section of conduit. For this example, assume a 2 inch PVC with a bunch of 14-2's and 12-2's.

1. Conduit must be at least 18 inches long (312.5 (C))
2. Fasten each cable within 12 inches of leaving the conduit (312.5 (C))
3. Install a threaded adapter and a plastic bushing at the top (what other "fitting" could be used?) (312.5 (C))
4. Strap the PVC in place (312.5 (C))
5. Seal the top with duct seal (312.5 (C))
6. Keep the sheaths on the cables and extend them into the panel at least 1/4 inch (312.5 (C))
7. Watch the cable fill from Chapter 9 (Where do you get the circular mils for a "flat" cable like NM?)
8. De-rate if and when required per 310.15(B)(2)(a)

Do you guys do this or is there a much simpler way? The AHJ is paranoid here about exposed NM so I can't run anything exposed, not even above the panel.
 
richwaskowitz said:
I have read and believe I understand 312.5 (C) but I just want to know if I am missing anything in the proper way to run multiple home-runs into a breaker panel when the panel is surface mounted (as in mounted on the wall in an unfinished basement) through a short section of conduit. For this example, assume a 2 inch PVC with a bunch of 14-2's and 12-2's.

1. Conduit must be at least 18 inches long (312.5 (C))
2. Fasten each cable within 12 inches of leaving the conduit (312.5 (C))
3. Install a threaded adapter and a plastic bushing at the top (what other "fitting" could be used?) (312.5 (C))
4. Strap the PVC in place (312.5 (C))
5. Seal the top with duct seal (312.5 (C))
6. Keep the sheaths on the cables and extend them into the panel at least 1/4 inch (312.5 (C))
7. Watch the cable fill from Chapter 9 (Where do you get the circular mils for a "flat" cable like NM?)
8. De-rate if and when required per 310.15(B)(2)(a)

Do you guys do this or is there a much simpler way? The AHJ is paranoid here about exposed NM so I can't run anything exposed, not even above the panel.
Click to expand...

It all sounds good but dose the inspector have any local amendments to back up his paranoia? 334.10 (1) and 334.10 (A) & (B)
 
I did my house that way many years ago and I still see some homes done this way. Perfectly legal. Interesting that you cannot stub down only up. :mad:
 
I haven't used that method yet, but I believe I saw a table somewhere that you can only fill up to 60% of total area if under 24"
 
Yeah,
Build a small box to cover the top of the panel. it'll look like a chase extending from the panel. 2 pieces of 2x4 couple sq/ft of drywall, you done.

richwaskowitz said:
I have read and believe I understand 312.5 (C) but I just want to know if I am missing anything in the proper way to run multiple home-runs into a breaker panel when the panel is surface mounted (as in mounted on the wall in an unfinished basement) through a short section of conduit. For this example, assume a 2 inch PVC with a bunch of 14-2's and 12-2's.

1. Conduit must be at least 18 inches long (312.5 (C))
2. Fasten each cable within 12 inches of leaving the conduit (312.5 (C))
3. Install a threaded adapter and a plastic bushing at the top (what other "fitting" could be used?) (312.5 (C))
4. Strap the PVC in place (312.5 (C))
5. Seal the top with duct seal (312.5 (C))
6. Keep the sheaths on the cables and extend them into the panel at least 1/4 inch (312.5 (C))
7. Watch the cable fill from Chapter 9 (Where do you get the circular mils for a "flat" cable like NM?)
8. De-rate if and when required per 310.15(B)(2)(a)

Do you guys do this or is there a much simpler way? The AHJ is paranoid here about exposed NM so I can't run anything exposed, not even above the panel.
Click to expand...
 
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