New home wiring question on Sub Panel

[jcragle]

I have a new home construction all DIY .. I am starting to get into the wiring phase of things and wanted to get some Q&A from the experts.

Is there any benefit to placing sub panels in major areas like the kitchen office space rec rooms other than the convenience of having the breakers for those items close to that area.

Consideration also that the wiring is not expansive… adding the sub panel would only shorten the run 20 ft or so.

[suemarkp]

Generally no. If you've done a good job, you should rarely or never have to reset a blown breaker, so convenience isn't really an issue. Adding a subpanel gives you two levels of voltage drop (the feeder to the subpanel and then the subpanel branch circuit). Your overall circuit lengths will be longer with a subpanel, and the biggest problem occurs when the panels get over 50 amps because the wire size gets so large. Running the big cable is harder, and metal nail guards become mandatory on both sides of the walls (unless you have 2x6 walls).

In general, I think it is easier to run a bunch of 12-2's through bored holes than a big feeder. I think one time to consider subpanels is if you have a room with growing and unknown electrical requirements (like a workshop). If the path from the room back to the main panel is difficult or impossible to work with for circuit additions, then putting a subpanel in that room could help. Conversely, you could also just run a large conduit to that room so future wires could be fished (or run multiple 10-3 or 6-3 cables to accomodate about anything). I would definitely run conduits between floors for low voltage wiring changes (CATV, phone, network), and maybe you'd want to do the same with separate conduits for future additions of power to each floor of the house.

[dremmel]

A sub-panel is beneficial if you have to run multiple circuits to an outbuilding such as a detached garage or workshop. Or if you need to run multiple circuits through a house that has a good amount of distance to travel. This way, you could run just your cable for the sub-panel from the main panel, and have a shorter distance to the loads, ie. lights, receptacles. But unless your house is a large home with a great deal of distance to travel for the individual circuits, you may not want to put in a sub-panel. You say you're into the wiring phase. Then you should have open (drywall isn't up yet) walls. If that's the case, run your circuits from the main panel and don't consider placing a sub-panel. Just my opinion.