Hello Everybody,

I am new here and hope that someone would be able to help me with this first question.

I am remodeling and would like to add a subpanel braker to the second story. The subpanel will be a 100 amp-double braker. What wire size should I use, and do I need to run it inside an EMT or flexible conduit from the main panel?

Thanks for any suggestion.

Typically, #2 aluminum 4 wire SER cable is used for something like this. There are a few areas, such as Chicago, that only conduit is allowed. So you should check with the local inspector for what would be allowed.

If you use conduit, you can still use #2 aluminum XHHW individual wires, or use a min of #4 copper THHN/THWN pulled wires.

Either way you need 4 wires, 3 for the two hots and one neutral, and either a #8 copper or # 6 aluminum for the equipment ground.

This is all taken care of with SER cable.

Be sure to keep the neutral separated at the subpanel using the neutral bar in the panel, do not bond it to the panel, and use a separate equipment ground bar for all bare and green equipment grounds, including the one from the feeder.

-What's meant by two story? Example: Single family home with two stories or other
-Your power will originate from where? Example: From the main service rated panel
-As far as in conduit or not, this will depend on your location. Example: Chicago requires conduit.

Tk and I must have posted at the same time! :)

Tk's on the money if this is a single family home with two floors.

The time stamp shows 16 minutes apart . I sometimes wonder about them when stuff like that happens to me. I try to give people the benefit of the doubt.

Yes, that's interesting!

Tk... I heard that Chicago has let up a bit on that reg requiring conduit. Not true? Man... that would make a sparky's life tough!

I do not keep up with other local changes. I have my own state and many towns to keep track of changes, waivers, etc.

According to their current website, does not appear so:
City of Chicago

Other than the MC allowance in existing homes in effect since 2000.

I had (moved two months ago) family in Chicago, and they wanted me to do work on their house, and at that time conduit was required. This was just this summer! Did I do the work? Nope! Seeing that they moved, I gave them good advice:)