What is the best way (meeting national electrical code) to add six 110v lines to attic apartment?

Question

New breaker box is in basement, rear of house (has already power to it). Half of the attic is being built as apartment, on the opposite end (front) of house. I need to run six individual 110v lines (that's what I want, that's what will be) with six breakers (about 10ft up from breaker box and 30ft to other end of house in the attic). Can one LARGE DIAMETER conduit be used to cary ALL SIX LINES to other end and then distributed, or I need six individual conduits? Can I use ONLY ONE WIRE (runing all the way back to box) to GROUND ALL SIX LINES? Seeking expert advice before starting ANYTHING.

Answer 1

Why not run one line to a sub panel in the attic space?

(At the price of cable today, it'll probably be cheaper.

Running & routing it would certainly be easier.)

3#6 + Gnd, from a 60A. 2p. in your main panel, and a

six circuit sub panel upstairs.

The Code rules on multiple conductors in a single

conduit would require you to oversize the six circuit runs.

The Code won't allow the single ground for the six

lines without a panel box and conduit.

Practically anywhere you are, a change of this

magnitude requires approval and inspection.

Talk to the local inspector. They'll tell you what they

want to see & when, and can be a very good source

of sound advice.

Answer 2

If you want to meet code, that would usually involve getting a permit - and that's a good idea.  

If, say there's a fire, and the insurance agent finds evidence of illegal wiring, the claim may be denied.

DIY work is a reasonable cost cutting measure *except* with things like electrical and gas piping - things that can affect the safety of you & your neighbors.

Excuse me while I get off of my high horse now...

Answer 3

If you will be renting the apartment, the NEC requires that the tenant have access to the panel for their space; you'll have to install a sub-panel.

The minimum service allowed to a residential dwelling is 100 Amperes; so THAT"S WHAT IT WILL BE, like it or not. Along with the 100 AMP service feeders, you will want to install a duplex meter cabinet, unless you are planning on paying for all of the electricity for both units. (If you will be living on the premises, you will only need 2 meters; if you will not be living there, and there are any "common areas" like stairs, hallways, outdoor lighting, you will need a third "house" meter). If you are going to live there, also, the common areas must be on the landlord’s bill.

For a 100 Amp service, you will need #3 AWG conductors for the service entrance; if your jurisdiction has not amended Table 310.15(6) out of the NEC, you can use #4 AWG conductors for the service entrance. If you install outside disconnects, both panels become sub-panels, and you must use #3 AWG conductors.

Sounds to me like you’re going to be out of your depth here, consult your local Building Department, check your local Zoning Ordinance, and then, hire a qualified, licensed electrical contractor to do the job (if you are allowed to). You may find that the Zoning Ordinance will not allow you to do this. (You will also want a separate water service and meter to the apartment, unless you want to pay for the water, also.)

Answer 4

One conduit, one ground wire large enough for the largest breaker, one neutral for each circuit is easiest to understand for the layman. 12 ga is not large enough for a 20 amp circuit in this situation. More than 10 current carrying conductors require  a 50% derating of the allowable ampacity.  There are different methods of doing a wiring project, but in this situation, you should call a qualified professional electrician to do the work.  A professional who is expeienced in multiple circuits in one conduit can make modifications and have only 9 conductors in a conduit.  Even in this case the wire must be derated to 70% of it's value.   Your easiest way is call a qualified professional electrician to do the work.

Answer 5

First of all the NEC is primarily a guideline and usually not all that's adopted and implemented by your municipality. . . and may not be accepted at all.  I was just in a city south of Tucson, Arizona on a project where they implemented the IBC, International Building Codes, so you really need to contact your loacl BD and ask to speak with the Electrical Inspector.  Now, if your looking to avoid permitting I strongly advise you to reconsider.  If there's every any issue, suc as a fire, that's said to be relevant to wiring you'll not only be in big trouble, but your insurance will have grounds and reason not to pay.

As to your question on how to:  You will need to install a sub panel or provide a completely new and seperate feed.  This will depend on the load calculations of what you are proposing to install and what your existing panel already supplys and what its rated at.

Answer 6

First you need to know electrical code can be different location to location.

Now since it is going to be an apartment you will want to give the renter access to their own breaker panel. To do this, put a 50 amp 240 volt breaker in your main box. Now run a 4 gage armored cable up to the apartment. The cable you will use is the same type you would use for an electric stove.

In the apartment you will install a 6 circuit sub panel box. All other circuits will feed back to this sub panel.

tcw