raceway is not more than 450 mm (18 in.) and remains in unbroken lengths (without coupling). Such raceway shall terminate in an outlet box, junction box, device box, cabinet, or other termination at each end of the raceway.
352.44 Expansion Fittings. Expansion fittings for PVC conduit shall be provided to compensate for thermal expansion and contraction where the length change, in accordance with Table 352.44, is expected to be 6 mm (!A in.) or greater in a straight run between securely mounted items such as boxes, cabinets, elbows, or other conduit terminations.
352.46 Bushings. Where a conduit enters a box, fitting, or other enclosure, a bushing or adapter shall be provided to protect the wire from abrasion unless the box, fitting, or enclosure design provides equivalent protection.
FPN: See 300.4(G) for the protection of conductors 4
AWG and larger at bushings.
352.48 Joints. All joints between lengths of conduit, and between conduit and couplings, fittings, and boxes, shall be made by an approved method.
352.56 Splices and Taps. Splices and taps shall be made in accordance with 300.15.
Table 352.44 Expansion Characteristics of PVC Rigid Nonmetallic Conduit Coefficient of
Thermal Expansion = 6.084 x 10~ 5 mm/mm/°C (3.38 x 10 -5 inVin/T)
|
Length Change of Temperature PVC Conduit Change (°C) (mm/m) |
Length Change of Temperature PVC Conduit Change (°F) (inVlOO ft) |
Temperature Length Change of PVC Change (°F) Conduit (inJlOO ft) |
|
5 0.30 10 0.61 15 0.91 20 1.22 25 1.52 30 1.83 |
5 0.20 10 0.41 15 0.61 20 0.81 25 1.01 30 1.22 |
105 4.26 110 4.46 115 4.66 120 4.87 125 5.07 130 5.27 |
|
35 2.13 40 2.43 45 2.74 50 3.04 |
35 1.42 40 1.62 45 1.83 50 2.03 |
135 5.48 140 5.68 145 5.88 150 6.08 |
|
55 3.35 60 3.65 65 3.95 70 4.26 75 4.56 |
55 2.23 60 2.43 65 2.64 70 2.84 75 3.04 |
155 6.29 160 6.49 165 6.69 170 6.90 175 7.10 |
|
80 4.87 85 5.17 90 5.48 95 5.78 100 6.08 |
80 3.24 85 3.45 90 3.65 95 3.85 100 4.06 |
180 7.30 185 7.50 190 7.71 195 7.91 200 8.11 |
352.60 Grounding. Where equipment grounding is re- quired, a separate equipment grounding conductor shall be installed in the conduit.
Exception No. 1: As permitted in 250.134(B), Exception No. 2, for dc circuits and 250.134(B), Exception No. 1, for separately run equipment grounding conductors.
Exception No. 2: Where the grounded conductor is used to ground equipment as permitted in 250.142.