Conduit/circuit question

[scatterbrained]

Hello:

I need to run 2 circuits from my basement panel to my attic (2 story house, approximately 90 feet from the panel). I had planned on running 2 hot and 2 neutral wires through a single conduit across the basement ceiling and up to the attic, then splitting the circuits there. Is this acceptible?

I planned on 12 gauge wire for 20 amp circuits (one is for lighting, the other for 2 outlets - 20 amps is really overkill). Can I use 1/2" conduit, or do I need to run 3/4"?

Thanks in advance!

Scatter'd

[HayZee518]

why in conduit? if you are running along ONE joist face use 12/3 romex. if you are running parallel to the joist faces, drill a hole at approx center of each joist, then run 12/3 to a junction box in the attic, then split it into TWO 12/2 circuits. splice all bare grounds together and to a metal box shell if you are using a metal junction box. At the panel use two single pole 20 amp breakers with a tie-bar or one two pole 20 common trip breaker

[scatterbrained]

conduit

Thanks! I just assumed I''d need to run conduit.

[HayZee518]

Nawww! don't need it in a residence. Conduit affords a mechanical protection for the wires. Romex can be installed along the building framework and stapled to it.

[jnaas2]

Do what hayzee said but use two seperate circuit breakers, make sure that they are installed on different phases in the panel. On most panels if you install 2 breakers side by side they will be on seperate phases this is how you get 240 volts. By running a 12/3 and and using the single white wire for both circuits is called a common ground and if you pull both circuits off of the same phase in the main panel the white wire will see all the amperage that the 2 circuits carry. So it is possible that the neutral wire could be carrying 40 amps what goes out must come back

[HayZee518]

JNaas yeah this is true but using a 12/3 constitutes a multiwire branch circuit and MUST be dealt with as a multiwire. the breakers feeding it must have a tie-bar or a common trip. That way if one trips it also takes out the other or you'd have a dead circuit and a live one in the same box. I understand the theory that the white or neutral would carry the imbalance of the circuit.

[MarcusF]

If you're still watching the thread

Don't wish to step on toes here, but this is for scatterbrained, if you're still watching the thread:

You show you're in Shorewood, Illinois on your profile.
Therefore, your first instincts were in fact correct, your new work, or extensions in your home MUST be in metalic conduit.

Shorewood, Illinois has adopted the 2002 NEC WITH AMMENDMENTS.

If yours is a one-family dwelling (Class B), all wiring shall be installed in metal rigid conduit, electrical metallic tubing or flexible metal conduit in short lenghts where flexible connections are necessary or by special permission.

You are not allowed to use romex (NM or NM-B) cable in your home.

Romex wouldn't be proper to bring up to your attic first anyway since that area is technically not conditioned and is considered a damp area at a minimum. You also have to pay special attention to the ambient temperatures of an attic environment and the operating conditions.

You are also required to use Metal Junction boxes and to have all of your work done with a permit and inspected.

You can visit the village website and follow the links to the village code to confirm this. The village code pertaining to electrical can be found in Title 8 Building Regulations, Chapter 1, Building Codes, Section Four, Sub-Section C "General Provisions". You will see at 8-1-4(C)(2) Classification of Wiring Methods And Materials, 8-1-4(C)(3) Extensions, and 8-1-4(C)(4) Boxes.

A Multi-wire circuit has its own issues.

Your best first resource is always your local building department/authority having jurisdiction. Your best first question is always what building codes and/or ammendments have been adopted in my jurisdiction.