Hint: Fill ‘r up
Unfortunately, it is not an uncommon sight for me to see PVC conduit separated from couplings and fittings. This is typically the result of expansion fittings not being installed where earth movement or thermal expansion and contraction cause the conduit to move around so much that connections at couplings and other fittings break. This photo is an example of what can happen when earth movement is not taken into consideration.
Section 300.5(J) requires direct-buried conductors, raceways, or cables subjected to movement by settlement or frost be arranged to prevent damage to the enclosed conductors or equipment connected to the raceways. While this Section may not specifically say that expansion fittings must be used, the Informational Note provides installers with important information about methods recognized as suitable for this purpose, including installing expansion fittings in raceways and “S” loops in direct buried cables and conductors.
