Unfinished Basement Wiring

My basement is unfinished and I am looking to do a temporary wiring job ( i may or may not finish the basement later on). I have a 100 amp sub panel in the basement to make things easier. Here is what I am planning to do.

Using 12-2 (I was thinking ROMEX), install a 20 amp breaker and install 3-4 new electrical outlets to be mounted against the concrete foundation. I have two electrical boxes that were installed by the builder and it looks as though the electrical wire came in from above, through a PVC conduit to a metal box. Below are my questions or issues:

I understand the first electrical box will need to be GFI. I plan on mimicking what the builder did as far as running the wire from the headers/joists to the box mounted on the foundation using conduit for each of my electrical boxes. I am unsure, however, how do run multiple receptacles on one breaker. To expand, do I install a junction box on the headers/joists or run 2 cables (a supply and return) through the PVC. If I install a junction box, can I run Romex down to my electrical box or does it have to be THHN? If I don't use junction boxes and run 2 - 12/2 Romex through conduit (for protection), is this allowed? Is the minimum PVC (Sch. 80) size 1 inch?

Also, I am assuming I will be using the metal electrical outlet boxes as well. Should I also be using metal Junction boxes - if that is the recommended route? How do i mount the electrical outlet boxes to the foundation?

I guess that's all I need help with. I can wire the boxes and the breaker just fine. I am just unsure about how to go from one outlet to the other. Any help is appreciated.

Thanks!

 

The easiest way to run these wires is to daisy chain them. The NM-B (Romex) goes to the first receptacle (GFI), then to the second, then to the third. You can fit 2 12/2 cables in a 1/2" conduit if it's just being used to sleeve and protect the wires.

You definitely want to use metal 4x4 boxes on the walls with cable clamps where the cables enter. They can be mounted with either tapcons or plastic masonry anchors and screws.

 

Thanks for the response...to daisy chain, would that require I sheathing the romex? I've heard bad things about overheating when placing two wires in the same conduit. I've also heard you should not unsheath the wires to run through the conduit.

 

Nope, you wouldn't unsheathe the cable. It would be 12/2 NM-B from the panel to the first box, with a cable clamp, then to the next, to the next.

Running Romex/NM-B in conduit is usually advised against, but in your case you'll be running it just 2 or 3 feet as protection. You'll still use a cable clamp (not a conduit clamp) at the box.

 

The sheath cannot be stripped off the NM when run in conduit.

Daisy chaining is just going from A to B to C etc.

 

I understand daisy chain. That would require to sheathed 12-2 romeo to be run through a conduit. Is there a overheat issue to be worried about...and code restriction?