Typical Trench Detail

  • Before digging call for Underground locates: (800) 332-2344 or 811 at least 48 hours prior to digging.
  • All Trenches must be a minimum of 36” deep.
  • If a 36-inch depth cannot be achieved, contact Lane Electric’s Engineering Department at (541) 484-1151.
  • If trench is to be a joint trench (shared with other utilities) the following separations must be maintained:
    • 24 inches between gas and electric lines
    • 12 inches between water and electric lines
    • 24 inches between sewer and electric lines
    • 12 inches between communications and electric lines
  • If trench is to be power only, the ditch needs be wide enough to accommodate the conduit, i.e. a 4-inch ditch-witch trench is sufficient.
  • If the trench is dug through rough, rocky terrain, the conduit must be bedded with a minimum of 4 inches of sand.
  • All conduits must be gray Schedule 40 electrical PVC.
  • All primary conduit (7200V) must be 3 inches in diameter with 36-inch radius long sweeping elbows at any 90° bend.
  • Secondary (120/240V) conduit for a 200 Amp. service must be 3 inches in diameter, with 36-inch radius long sweeping elbows at any 90° bend.
  • Secondary (120/240V) conduit for a 400 Amp. service must be 3 inches in diameter, with 36-inch radius long sweeping elbows at any 90° bend. (See Exhibit A)
  • Street or security lighting conduit must be 1.25 inches with 36-inch radius long sweeping elbows at any 90° bend.
  • There will be no more than 270° of bend (3- 90° bends or 2- 90° &   2- 45°) in any one run of conduit, primary or secondary, between devices.
  • All Primary conduits must be proved by mandrel.  See Exhibit I for mandreling details.
  • New mule-tape rated at 2500# must be left in all conduits, primary and/or secondary. Mule-tape must move freely in conduit and have sufficient length (10 feet or greater) beyond each end to accommodate installation of conductor.  Mule-tape can be picked up at Lane Electric at no charge.
  • Where transformers and primary or secondary junction boxes are to be installed, specifications must be obtained from Lane Electric’s Engineering Department.  (See Exhibits B-G for common facilities.)
  • After the Trench is dug and conduit installed, call Lane Electric (541) 484-1151 to have an inspection scheduled by the Engineering and Operations Department.
  • After the Trench and the conduit are inspected, the Trench may be back-filled.  Conductor cannot be installed until trench is backfilled.

Diagram of typical trench detail drawingNote: No electric lines, primary or secondary, may be placed under a concrete foundation or slab.

For more information, view the Typical Trench Detail Information (PDF).