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Monday, November 2, 2020
Question:
Hello CQD,
Is an expansion coupling required on a riser "PVC SCH 80" that goes in the ground 18" and terminates at the bottom of the meter or electrical box? This installation is where the service conductors are buried at 24" and not in conduit. Conductors are only in the risers in a straight conduit the last 42"= 18" below grade and 24" exposed.
Jeff Determan
A
Answer:
Hi Jeff,
Thanks for the question. The key to this question rests whether or not there is anticipated earth movement from the settlement of frost. Section 230.32 indicates that underground service conductors be protected in accordance with Section 300.5. In section 300.5(J), which is titled "Earth Movement," indicates where direct-buried conductors, raceways, or cables are and subject to movement by settlement or frost, direct-buried conductors, raceways. Cables shall be arranged to prevent damage to the enclosed conductors or to equipment connected to the raceways. There is an Informational Note which explains this section, recognizes “S” loops in underground direct burial cables. And conductors to raceway transitions, expansion fittings in raceway risers to fixed equipment, and, generally, the provision of flexible connections to equipment subject to settlement or frost heaves. It's also, recommended that you refer to the local utility company service requirements. They may have a mandatory requirement for installing expansion fittings in the riser conduit mentioned in the question.