3" PVC Sch 40 conduit fill
3" Rigid PVC conduit, Schedule 40 has an inside area of 7.268 sq in (3.042 in across). Three or more wires may take 40 % of it: 2.9072 sq in.
- One wire, 53 %
- 3.8520 sq in
- Two wires, 31 %
- 2.2531 sq in
- Three or more, 40 %
- 2.9072 sq in
- Nipple, 60 %
- 4.3608 sq in
- Support
- Every 6 ft, 3 ft from boxes
- Sold in
- 10 ft sticks
How many wires fit in 3" PVC Sch 40
All wires the same size and type, by Annex C's method. For a mix of sizes, open the calculator.
| Wire size | THHN/THWN-2 | XHHW-2 | THW/THW-2 |
|---|---|---|---|
| 14 AWG | 299 | 209 | 209 |
| 12 AWG | 218 | 160 | 160 |
| 10 AWG | 137 | 119 | 119 |
| 8 AWG | 79 | 66 | 66 |
| 6 AWG | 57 | 49 | 40 |
| 4 AWG | 35 | 35 | 30 |
| 3 AWG | 30 | 30 | 25 |
| 2 AWG | 25 | 25 | 22 |
| 1 AWG | 18 | 19 | 15 |
| 1/0 AWG | 15 | 16 | 13 |
| 2/0 AWG | 13 | 13 | 11 |
| 3/0 AWG | 11 | 11 | 9 |
| 4/0 AWG | 9 | 9 | 8 |
| 250 kcmil | 7 | 7 | 6 |
| 300 kcmil | 6 | 6 | 5 |
| 350 kcmil | 5 | 5 | 5 |
| 400 kcmil | 5 | 5 | 4 |
| 500 kcmil | 4 | 4 | 3 |
| 600 kcmil | 3 | 3 | 3 |
| 700 kcmil | 3 | 3 | 2 |
| 750 kcmil | 2 | 2 | 1 |
| 800 kcmil | 2 | 2 | 1 |
| 900 kcmil | 1 | 1 | 1 |
| 1000 kcmil | 1 | 1 | 1 |
Other 3" conduit
| Conduit | Inside area | #14 | #12 | #10 | #8 | #6 |
|---|---|---|---|---|---|---|
| Rigid PVC conduit, Schedule 40 | 7.268 | 299 | 218 | 137 | 79 | 57 |
| Electrical metallic tubing | 8.846 | 364 | 266 | 167 | 96 | 69 |
| Intermediate metal conduit | 7.922 | 326 | 238 | 150 | 86 | 62 |
| Rigid metal conduit (RMC, GRC) | 7.499 | 309 | 225 | 142 | 82 | 59 |
| Rigid PVC conduit, Schedule 80 | 6.442 | 265 | 193 | 122 | 70 | 51 |
| Flexible metal conduit (FMC, Greenfield) | 7.069 | 291 | 212 | 134 | 77 | 55 |
| Liquidtight flexible metal conduit (LFMC) | 7.475 | 308 | 225 | 141 | 81 | 59 |
About PVC Sch 40
Schedule 40 is the standard PVC wall. Support spacing gets wider as the size goes up (Table 352.30), and long runs in the sun need expansion fittings (352.44). See strap spacing and the fill rules.