Underground Service Entrance Cable Requirements

How to translate the electrical wire markings on nmc cable.

Underground service entrance cable requirements.

In general bury the nonmetallic conduits 18 inches below grade or 12 inches if protected by 2 inches of concrete or equivalent. Nec 300 5 underground wiring conduits and raceways direct buried cable or conduit or other raceways shall meet the following minimum cover requirements. Meter base mounted on exterior wall of house or mobile manufactured home. At 18 inches you can use thwn 2 conductors inside a continuous length of pvc conduit which protects the wire all the way through the trench to the house.

Single mobile home underground service alternate meter pedestal figure 10. Requirements for nonmetallic conduits nonmetallic conduits or raceways approved for buried cable give less protection than metal conduits and require greater burial depths. Service entrance disconnect and location shall conform to the latest version of the nec and all local ordinances. At 24 inches you can bury underground feeder cable using pvc conduit to 18 inches below ground only where the wire comes up.

Cu copper. Minimum 6 copper ground wire securely stapled to wall. Direct burial cable rigid or intermediate metal conduit non metallic raceway pvc 24 inches 6 inches 18. 14 2 wg 14 gauge 2 conductors with ground etc.

According to 338 2 there are two types of service entrance cables. 14 2 14 gauge 2 conductors etc. Single phase underground service meter installation figure 9. For overhead service weather head must be a minimum of three feet above the roof.

A disconnecting means must be provided for all. 5trenches to be in as straight and direct a line as possible. Any conduit crossing under a road shall be schedule 80. Current transformer cabinets overhead or underground service window type ct s figure 11.

Al aluminum conductor. For underground service the poured footing must be notched out for the conduit. For service entrances of 201 to 400 amperes as determined by the nameplate ampacity of the service disconnect a rain tight current transformer enclosure constructed of code gauge metal with an approved mounting base for bar type current transformers shall be used. Single mobile home underground service pressure treated post figure 9a.

Conduits installed less than 36 inches in depth require cooperative engineering approval and shall beencased in concrete to cooperative specs depths specified are to finished grade. 600 v maximum voltage rating for typical residential nm electrical cable.