Page 47 - puget sound energy community energy programs

Chapter 4

Customer-provided trench

Trench width The minimum trench width is 18 inches. The excavator may need to increase the
trench width depending on the other conduits/lines being installed in the trench.
When increasing the trench width, remember to allow adequate horizontal separation
between PSE’s electrical conduits/cables, gas lines, and other utility-owned conduits
and lines in the trench (see Figure 22).
Customer-owned facilities may not be in the same trench with PSE-owned gas lines.
PSE will allow customer-owned facilities within an electric power trench if the following
minimum horizontal clearances from PSE electric facilities are maintained:
• 18 inches minimum for customer-owned tight-line sewer (not tile), storm drain
lines, roof drain lines, natural gas line, propane gas line, fuel oil line, and water
mains up to 6 inches.
• 12 inches minimum for water services, irrigation pipes, lighting, security and
electric supply circuits, communication lines, closed-system roof drains/storm
drains (not French drains), and culverts.
NOTE: When constrained by obstructions or clearances from other buried utility
lines/facilities, the horizontal clearance between PSE power and communications
may be reduced to 4 inches with mutual agreement from the participating
communications providers. It is your responsibility to obtain agreement from
participating communications providers for a reduced clearance when needed.
Figure 22 illustrates PSE’s width and depth requirements for primary voltage cable
residential line extension trenches on private property with and without a gas line
present.

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Electric Service Handbook 2017 — Single-Family Residential Projects 38