1/2" PVC Schedule 40 has 0.602" inside and 0.285 in² of area, so the 40 % fill limit is 0.114 in². It holds 11 × 14, 8 × 12, 5 × 10, 3 × 8 or 1 × 6 AWG THHN. A 60 A EV run (two 6 AWG and a 10 AWG ground) fills it 43 %: too full.
03 · Conduit fill · Chapter 9 Tables 1, 4 & 5
USE:
1/2" PVC 40 · 18.7% FILL · PASS
4 conductors take 0.0532 in² of the 0.285 in² inside 1/2" PVC 40: 18.7 % against the 40 % allowed.
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| Actions | |||||
|---|---|---|---|---|---|
| 13.6 % | 0.0752 in² | 5 | 3 | ||
| 18.7 % | 0.0608 in² | 4 | 2 | ||
| 29.6 % | 0.0296 in² | 2 | 1 | ||
| 45.9 % over | over by 0.0169 in² | — | — | ||
| 14.0 % | 0.0741 in² | 5 | 3 | ||
| 23.3 % | 0.0475 in² | 3 | 2 | ||
| 32.7 % | 0.0209 in² | 1 | 0 |
gnd: Table 250.122 ground. 1/2" PVC 40 allows 0.114 in² at 40 %.
05 / Field guide
1/2" PVC Schedule 40 has 0.602" inside and 0.285 in² of area, so the 40 % fill limit is 0.114 in². It holds 11 × 14, 8 × 12, 5 × 10, 3 × 8 or 1 × 6 AWG THHN. A 60 A EV run (two 6 AWG and a 10 AWG ground) fills it 43 %: too full.
1/2" PVC Schedule 40 (Article 352) has 0.285 in² inside. One conductor may fill 53 % (0.151 in²), two 31 % (0.088 in²), three or more 40 % (0.114 in²). A nipple 24" or shorter may take 60 % (0.171 in²): 13 × 12 AWG.
fill % = Σ Table 5 areas ÷ 0.285 in²
1/2" Schedule 40 is 0.840" outside and 0.602" inside (0.119" wall). PVC is not a grounding path: pull an insulated ground.
Secure 1/2" PVC Schedule 40 within 3 ft of each box and support it at least every 3 ft (352.30). At 17 lb per 100 ft, each 3 ft span hangs 0.5 lb of pipe. A 60 A EV run (43.0 %) does not fit; nor does a 60 A subpanel feeder (60.8 %).
For a mix, add the areas. Two 6 AWG and a 10 AWG ground (a 60 A EV run) take 0.1225 in², 43.0 %; three 3 AWG and an 8 AWG (a 100 A subpanel) take 0.3285 in², 115.3 %.
Questions
8 THHN conductors at the 40 % limit (0.114 in² ÷ 0.0133 in²); 8 current-carrying 12 AWG are derated to 70 % (310.15(C)(1)).
5 THHN, or 4 XHHW (thicker insulation, 0.0243 in² against 0.0211 in²).
Within 3 ft of every box or fitting and at least every 3 ft along the run (NEC 352.30, Table 352.30): a 50 ft straight run takes 16 straps, a 100 ft run 33. Keep the bends between pull points to 360° or less (352.26).
Three 6 AWG THHN and a 10 AWG ground take 0.1732 in², 60.8 % of 0.285 in²: over the 40 % limit; use 3/4" PVC 40.
0.602 inch nominal (NEC Chapter 9 Table 4), 0.840 inch outside. Use the inside area, 0.285 in², for fill.
8 AWG THHN: three fit within 40 %.
6 % smaller than 1/2" EMT (0.304 in²).