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#33146 - 01/13/04 12:47 PM wire capacity of 1/2 inch conduit
cpalm1 Offline
Member
Registered: 01/06/04
Posts: 66
i have a 1/2 inch conduit that runs from my panel to the far side of my house and supplies 2 rooms, a hallway and a garage.
currently this pipe contains three 15 amp circuits and a 20 amp circuit. these are multiwire circuits. there are 4 14 gague wires and 2 12 gauge wires.

could i add an additonal 2 amp circuit? to do this i would need to pull an additonal 12 gauge wire and a 14 gague neutral.

then i would have 4 15 amp circuits and 2 20 amp circuits.

simply put, the pipe would contain 6-14 AWG (4 current carrying) and 3 12 AWG (2 current carrying) would this be ok, or would the pipe be over stuffed?
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#33147 - 01/13/04 01:21 PM Re: wire capacity of 1/2 inch conduit
George Offline
Member
Registered: 02/23/02
Posts: 375
It appears that the answer is you can not, but I just did a rough calculation.
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#33148 - 01/13/04 01:35 PM Re: wire capacity of 1/2 inch conduit
resqcapt19 Offline
Member
Registered: 11/10/00
Posts: 2148
Loc: IL
What is the wire type? If it is THHN there is not a problem with the conduit fill or with the ampacity adjustment for more than 3 current carrying conductors.
Don
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Don(resqcapt19)
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#33149 - 01/13/04 04:25 PM Re: wire capacity of 1/2 inch conduit
cpalm1 Offline
Member
Registered: 01/06/04
Posts: 66
The wire is THHN
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#33150 - 01/13/04 06:52 PM Re: wire capacity of 1/2 inch conduit
Jim M Offline
Member
Registered: 08/10/01
Posts: 457
Loc: Chestertown, MD, USA
Why would you pull a 14 ga. neutral with a 20 ga. hot?
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#33151 - 01/13/04 07:01 PM Re: wire capacity of 1/2 inch conduit
cpalm1 Offline
Member
Registered: 01/06/04
Posts: 66
because the there is a multiwire system in the pipe that has a 20 amp and 15 amp circuit. when i add the second 20 amp, i plan to use the 12 gauge neutral that is already in the box, and pull a new neutral for the old 15 amp ciruit that is currently sharing the old 20 amp circuit's neutral.
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#33152 - 01/13/04 07:04 PM Re: wire capacity of 1/2 inch conduit
cpalm1 Offline
Member
Registered: 01/06/04
Posts: 66
basically i would end up with a total of 5 circuits. there would be 3 15 amp circuits. 2 of them would share a neutral and one would have it's own neutral (the 14 gauge that i am pulling). The new hot 12 gauge would be hooked up to the old 12 gague neutral. of course i would make sure all of the breakers for the multiwire circuits are on opposite 120V legs.
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