# Conduit Fil

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#### TWGJ24

##### Member
Say we have a 3/4 PVC Sch. 40 Conduit 100 feet long. How many number 12 Thhn wires can I put in this conduit if I am using diveristy and each circuit is non continuous load of 1200w. I am figuring that I can put in 12 Current carrying conductors. IF I am wrong please explain why and how you come up with something else.
Thanks

#### Dennis Alwon

##### Moderator
Staff member
Two things you must do. Figure how many conductors will fit in the conduit then determine the number of ccc and derate. This question cannot be answered because we don't know if the load is 120V on a single phase or three phase system. We also don't know if the load is 120 or 240. I would assume 120V.

#### infinity

##### Moderator
Staff member
What table are you using for your diversity calculations? If you use the standard derating table {TABLE 310.15(B)(3)(a)} your 12 CCC's would require an adjusted ampacity of 50% which equals 15 amps. (30 * 50% = 15) For a 1200 watt load your good on a 15 amp OCPD.

#### Dennis Alwon

##### Moderator
Staff member
Actually I think it will work out the same for single phase or 3 phase but I think 12 is not correct. You say 12 CCC but the question is how many conductors.

#### infinity

##### Moderator
Staff member
You can fit 15-#12 THHN conductors in a Sch-40 PVC. He said 12 CCC's so that's possibly 6-120 volt circuits.

#### david luchini

##### Moderator
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You can fit 15-#12 THHN conductors in a Sch-40 PVC. He said 12 CCC's so that's possibly 6-120 volt circuits.
So, 14 CCC's and one equipment ground (#12 THHN) would be the correct answer.

#### infinity

##### Moderator
Staff member
So, 14 CCC's and one equipment ground (#12 THHN) would be the correct answer.
Yup, that would work if all of the circuits could operate on 15 amp OCPD's.

#### david luchini

##### Moderator
Staff member
Yup, that would work if all of the circuits could operate on 15 amp OCPD's.
Yes, and with 15 OCPD's, we could put twenty (20) #14 THHN CCCs and one EGC in the 3/4" PVC to handle the 1200W loads...assuming the loads are not multiple receptacle outlets for cord-and-plug connected portable loads.

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#### infinity

##### Moderator
Staff member
Yes, and with 15 OCPD's, we could put twenty (20) #14 THHN CCCs and one EGC in the 3/4" PVC to handle the 1200W loads...assuming the loads are not multiple receptacle outlets for cord-and-plug connected portable loads.
Yes, unless the PVC is longer than 24".

Staff member

#### infinity

##### Moderator
Staff member
At 40% fill, the maximum #12 THHN conductors that you can put in that 3/4 Sch 40 is 15.

#### Dennis Alwon

##### Moderator
Staff member
At 40% fill, the maximum #12 THHN conductors that you can put in that 3/4 Sch 40 is 15.
David's last post was about 14 gauge.

#### infinity

##### Moderator
Staff member
David's last post was about 14 gauge.

Ahh that makes more sense. He changed the wire size from the OP #12's to #14's. Sneaky.