Space, Safety and Money vs. Wire
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Space, Safety and Money vs. Wire
I'm adding 6 new circuits to my system, and I have a question about what type of wire to use.
To get from the panel to the area of the house where I need the new circuits, I have only a small chase to bring up the cables. The chase is probably 3" by 2", and about 12' long.
I believe I have enough room to bring through six 12-2 cables, but I feel like it would get crowded, take more time, and in general just add a lot of cables to an already crowded area of the house. A subpanel is not an option (nowhere to put it).
My questions:
Is there a restriction as to how many 12-2 cables can occupy a given area (not in a conduit)?
Would I be better off using 12-3, to go from 6 cables to 3?
Would I be better off using 12-4, as opposed to 12-3?
What makes the most sense to you guys?
Thanks.
To get from the panel to the area of the house where I need the new circuits, I have only a small chase to bring up the cables. The chase is probably 3" by 2", and about 12' long.
I believe I have enough room to bring through six 12-2 cables, but I feel like it would get crowded, take more time, and in general just add a lot of cables to an already crowded area of the house. A subpanel is not an option (nowhere to put it).
My questions:
Is there a restriction as to how many 12-2 cables can occupy a given area (not in a conduit)?
Would I be better off using 12-3, to go from 6 cables to 3?
Would I be better off using 12-4, as opposed to 12-3?
What makes the most sense to you guys?
Thanks.
#2
Yes, You would have to use 2 pole breakers but it is a small price to pay for pulling in half the cables. Also your wires would then be 9 in the bundle. Derating factor is 70% at 9 wires. THHN is rated at 30 amps under the 90 degree column 30 x .70 = 21 amps so you are still fine at 20 amps.
With the extra cost of 12/4 you would likely not gain anything compared with using two pole breakers. Plus you would now have 12 current carrying wires which means you would be at 50% derating factor. 30 x .50 = 15 amps
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Thanks Toblyn.
Let me just add this twist, since you brought up two pole breakers:
The new circuits would need to tie into tandem breakers. So if I went with 12-3, I would be able to pull fewer cables, but would need to be mindful to keep the both "hots" from each 12-3 on a separate phase inside the panel?
Let me just add this twist, since you brought up two pole breakers:
The new circuits would need to tie into tandem breakers. So if I went with 12-3, I would be able to pull fewer cables, but would need to be mindful to keep the both "hots" from each 12-3 on a separate phase inside the panel?
#4
Yes, both hots will need to land on separate phases, otherwise you risk overloading the neutral. I should have mentioned the two pole breaker rule went to effect as of 2008 code. If your not on 2008 code single pole breakers are fine. If you are on 2008 code you will be required to get two pole tandems which ups the cost a bit depending on your type panel. I should also mention if this is for a bedroom AFCI breakers come into play as of 2005 code and other general areas (except bathrooms or kitchens) as of 2008 code.
Are you sure there is no place to install a sub panel? Many cases they can be quite camouflaged with a cabinet door or placed behind a person door.
Are you sure there is no place to install a sub panel? Many cases they can be quite camouflaged with a cabinet door or placed behind a person door.
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I've been poking around since I made my initial post. A subpanel might actually work, I'd just have to extend the cables a few feet farther. A little more information, than a couple of questions:
My house is a duplex. In my basement I have a main panel that only feeds two other panels (call them A and B). Panel B is the panel that I had intended to take the 6 new circuits out of.
There are 8 breaker spaces in Panel B. Two are occupied by the main shut off, two are occupied by a 30amp range, two are in use by existing circuits, and two are empty. If I were to install a subpanel after panel B to handle the 6 new circuits, what size cable would I use?
My house is a duplex. In my basement I have a main panel that only feeds two other panels (call them A and B). Panel B is the panel that I had intended to take the 6 new circuits out of.
There are 8 breaker spaces in Panel B. Two are occupied by the main shut off, two are occupied by a 30amp range, two are in use by existing circuits, and two are empty. If I were to install a subpanel after panel B to handle the 6 new circuits, what size cable would I use?
#6
If I were to install a subpanel after panel B to handle the 6 new circuits, what size cable would I use?
#7
If I were to install a subpanel after panel B to handle the 6 new circuits, what size cable would I use?
#8
You could change out the small panel for a larger one.
IIRC Cutler-Hammer is the only one making two-pole AFCIs.
IIRC Cutler-Hammer is the only one making two-pole AFCIs.
#10
You need a space 30" wide by 36" deep. The panel does not need to be centered in the 30" width. Imagine a refrigerator size box in front of the panel. You also need lighting. The panel door needs to be able to open at least 90 degrees. You should not have piping or ductwork in the panel workspace.
#11
You also may not have a panel in a bathroom or a clothes closet. You may have a panel behind a a door when it is open. We have many times put one in a bedroom behind the door. The only time you will see it is when the door is shut. Even then you an put a cabinet door to make it look nice.