Electrical question

[Nathan (SD)]

I have a building restoration project going on. I have a new breaker box in the new construction area. The new building is ajoined to the old in a somewhat crude fashion. The power in the old part was supplied through a fuse box that was removed some time ago before my arrival. I took an extension chord recently and powered up each circuit individually and they work fine. I need to get power from the breaker box to these individual lines which are in the rafters. I could get a conduit through the rafters from the breaker box over to the area of the old original wires and join them in a large junction box. I have 2 circuits that are 220 volt 12g feeding small heaters. I have 3 cuircuits that are 120 volt 12g feeding lights and outlets.

My question is, can I feed all these lines in 1 conduit? I am confused how many current carrying conductors I have in this situation ? Do I have 7 or 10 ?

The 2 heaters need 20 amp breakers. I would like the 120 volt lines to have 20 amp breakers also. Can all these be fed with a single conduit per NEC code ?


Thanks in advance.

 

[David G]

You can put as many wires in a conduit as wanted, as long as you adhere to the limits.

Now, I am not following what you are doing.

I prefer 1 large breaker in main panel going to sub panel, then feed from there.

 

[Kansasredneck]

You will have ten current carrying conductors. Given the cost of wire, you might be better off to run an aluminium 70 amp feeder and a sub panel.

 

[Paul from MI]

There are de-rating rules when more than three wires are in a conduit. Be sure to follow them.

 

[Nathan (SD)]

The panel would have to be in the attic. I don't want to have to crawl in the attic if a breaker trips.

Is more conduits my only solution ?

 

[Steve@Advance]

You can run multiple circuits in a single conduit.

There are fill charts to determine the size conduit needed. The bends can not exceed 360*, not counting offsets.

 

[Nathan (SD)]

Only about 30ft from breaker box to wires.

 

[Kansasredneck]

Yes. If you try to put that many circuits in one conduit you must derate the circuits. As a matter of practice, we limit it to four circuits per conduit.
So run two conduits.

 

[Stephen Newell]

Unless it's commercial and the local codes call for conduit I would run individual pieces of conduit per circuit. A residential code should allow you to just pull romex without the conduit.

Personally if it were me I would put in a sub-panel in the new addition and feed everything off that.

 

[billfromwisconsin]

I would get a small subpanel and put it where the original fuse box was, then make one run to the subpanel. You can get sub panels with breakers in them.

 

[pinball]

first thing is to check the wiring so see what the current rating is for your breakers. 20 amp breaker using 15 amp wire is bad.

 

[Olliejunkie]

If you're worried about code I would call your local inspector. I have been on many jobs and preached debating but no one paid any attention for it and no inspector called them on it. All we worried about was wire fill. I haven't been on a job in 3 years so I'm not up on what they're practicing now. You could also look into a code book . I dont have a recent one. Or you could just put in more conduits.

 

[Check Break]

(quoted from post at 19:06:21 11/21/20) I have a building restoration project going on. I have a new breaker box in the new construction area. The power in the old part was supplied through a fuse box that was removed some time ago before my arrival. I took an extension chord recently and powered up each circuit individually and they work fine. I need to get power from the breaker box to these individual lines which are in the rafters. I could get a conduit through the rafters from the breaker box over to the area of the old original wires and join them in a large junction box. I

My question is, can I feed all these lines in 1 conduit? I am confused how many current carrying conductors I have in this situation ? Do I have 7 or 10 ?

The 2 heaters need 20 amp breakers. I would like the 120 volt lines to have 20 amp breakers also. Can all these be fed with a single conduit per NEC code ?

This is not a direct answer to your question. Why conduit. You can run Romex from your new panel to each circuit. Use a 2 gang box with cover as a junction box for each circuit. If your circuits in the attic do not terminate in the same place, your Romex runs will be easier than conduit. If possible, install the j boxes in places which are easiest to access.

 

[Olliejunkie]

I should ad we seldom ran bigger than 3/4 for number 12 wire. Maybe we only put 6 circuits in but that would still be 12 current carrying conductors plus ground as each conductor had it's own neutral.

 

[dr sportster]

What I would do is run a new romex to each old end and use smaller boxes and multiple splices .Bending pipe in close quarter will drive you nuts . Look on line for how many wires in a 3/4 conduit { 1/2 is small and not allowed in many locations] Treat each circuit as a separate job .

 

[dr sportster]

Can 't exceed 360 without a box.

 

[dr sportster]

16 #12gauge wires in a 3/4 conduit {unless it is less than a 24" nipple]

 

[Nathan (SD)]

(quoted from post at 19:37:48 11/21/20) Yes. If you try to put that many circuits in one conduit you must derate the circuits. As a matter of practice, we limit it to four circuits per conduit.
So run two conduits.

A 20 amp breaker on a 12g wire is still a go in that scenario correct ?

 

[Nathan (SD)]

A 20 amp breaker on a 12g wire is still a go in that scenario, correct ?