NEC 300.7 Raceways Exposed to Different Temperatures, with NEC 2005 different from NEC 2008 | For discussion only.

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NEC 300.7 Raceways Exposed to Different Temperatures, with NEC 2005
different from NEC 2008. For ground-mounted array would be likely NEC
300.5. Temperature in sunlight, roofops or underground may be a
different temperature, right? For instance, 2008 Table 310.15(B)(2)(c)
Ambient Temperature Adjustment for Conduits Exposed to Sunlight On or
Above Rooftops

For example, a ~21 degree C increase would be approximately 2.48
inches per 100 feet of PVC Rigid Nonmetallic Conduit? Correct? But,
if in accordance to 2005 & 2008 NEC 300.7 (B) FPN for "steel
electrical metallic tubing, intermediate metal conduit, and rigid
conduit ..." would be 2.84 * .2 = ~0.568 inches nominal -~0.546
inches Correct? In addition further calculations may be calculated
for "A nominal number for aluminum conduit and aluminum electrical
metallic tubing " ...

"FPN: Table 352.44 and Table 355.44 provide the expansion information
for polyvinyl chloride (PVC) and for reinforced thermosetting resin
conduit (RTRC), respectively. A nominal number for steel conduit can
be determined by multiplying the expansion length in Table 352.44 by
0.20. The coefficient of expansion for steel electrical metallic
tubing, intermediate metal conduit, and rigid conduit is 1.170 × 10−5
(0.0000117 mm per mm of conduit for each °C in temperature change)
[0.650 × 10−5 (0.0000065 in. per inch of conduit for each °F in
temperature change)]. A nominal number for aluminum conduit and
aluminum electrical metallic tubing can be determined by multiplying
the expansion length in Table 352.44 by 0.40. The coefficient of
expansion for aluminum electrical metallic tubing and aluminum rigid
metal conduit is 2.34 × 10−5 (0.0000234 mm per mm of conduit for each
°C in temperature change) [1.30 × 10−5 (0.000013) in. per inch of
conduit for each °F in temperature change]."

NEC 352.30 Securing and Supporting. PVC conduit shall be installed as
a complete system as provided in 300.18 and shall be fastened so that
movement from thermal expansion or contraction is permitted. PVC
conduit shall be securely fastened and supported in accordance with
352.30(A) and (B) or permitted to be unsupported in accordance with
352.30(C)."

NEC 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 (1⁄4 in.) or greater in a straight run between securely
mounted items such as boxes, cabinets, elbows, or other conduit
terminations."

NEC Table 352.44 "Expansion Characteristics of PVC Rigid Nonmetallic
Conduit Coefficient of Thermal Expansion = 6.084 × 10−5 mm/mm/°C (3.38
× 10–5 in./in./°F)"

2008 NEC Table 355.44 "Expansion Characteristics of Reinforced
Thermosetting Resin Conduit (RTRC) Coefficient of Thermal Expansion =
2.7 × 10–5 mm/mm/°C (1.5 × 10–5 in./in./°F)"

NEC 378.44 Expansion Fittings. Expansion fittings for nonmetallic
wireway shall be provided to compensate for thermal expansion and
contraction where the length change is expected to be 6 mm (0.25 in.)
or greater in a straight run. FPN: See Table 352.44 for expansion
characteristics of PVC conduit. The expansion characteristics of PVC
nonmetallic wireway are identical.