Burying outdoor extension cords can be a convenient way to provide power to outdoor areas without running unsightly cords above ground. However, there are important safety considerations to keep in mind when burying cords to avoid electric shock or fire hazards. In this comprehensive guide, I will provide in-depth instructions on how to safely bury extension cords outdoors.
Selecting the Right Extension Cord
The first step is choosing an extension cord specifically designed and rated for burial. Look for cords labeled as "sunlight resistant," "burial-grade," or "underground-feed" on the packaging.
Some key factors to consider when selecting a burial-grade outdoor extension cord:
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Wire gauge - Heavier 12 or 10 gauge wire is best for burial as it is less prone to damage and is safer for outdoor use. Lighter gauge cords can overheat.
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Waterproofing - Choose a cord with waterproof or water-resistant jacket for protection when buried.
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UL approval - Select a cord that is UL (Underwriters Laboratories) approved for outdoor and wet locations.
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Length - Purchase an adequate length so you don't have to splice cords. Opt for a little longer than needed.
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Number of outlets - Choose a cord with enough outlets to power all outdoor devices needed.
Selecting the proper cord for underground use is crucial to prevent shock or fire risks. Never use a regular indoor/outdoor extension cord for burial.
Digging the Trench
Once you have the right cord, the next step is to dig an appropriate trench to bury the cord:
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Dig a trench 12-18 inches deep and 6-12 inches wide. This allows space to safely accommodate the cord and any connectors.
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Make sure to call 811 before digging to have underground utility lines marked so you avoid severing any lines.
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Avoid burying under structures like decks, sheds or patios which may compress the cord over time.
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Run the trench from the power source to the outlet location in a straight line if possible. Avoid sharp bends.
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Slope any long runs to allow drainage and prevent pooling water.
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Clear the trench of rocks, sticks and sharp objects that could damage cord.
Digging a proper trench helps protect the cord and maintains accessibility for any future repairs needed.
Running and Protecting the Cord
When running the extension cord through the trench, here are some key steps to take:
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Unroll the cord and run it through the trench. Avoid pulling hard on the cord.
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Leave some slack to prevent tension on the cord once buried.
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Use PVC conduit to encase the first 12-18 inches of cord exiting the power source to protect the connection.
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Install junction boxes above ground wherever cords connect for accessibility.
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Use waterproof tape or silicone to seal any connection points in the cord jacket.
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Attach the cord to the bottom of the trench in a few places with landscaping staples to hold it in place when backfilling.
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Label both ends of the cord with notes on the burial location for future reference.
Properly positioning the cord in the trench and securing connections will enhance safety and longevity.
Backfilling and Finishing Touches
The final step is to backfill the trench and make it look presentable:
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Backfill with dirt/soil removed when digging the trench, free of rocks or debris.
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Hand pack soil firmly around the cord to cushion it, but avoid excessive compaction.
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Mound soil slightly to allow for settling over time.
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Consider marking the location with buried caution tape or wire above the cord, especially for long runs.
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Install gravel or sod over the trench line to allow mowing but indicate buried cord.
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For permanent installations, pour a thin layer of concrete over the backfilled trench to protect the buried cord.
Taking care when backfilling and marking the location will properly cover the cord while still maintaining access.
Safety Precautions When Using Buried Cords
Once successfully installed, be sure to take these safety measures when using buried extension cords:
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Use a GFCI outlet or breaker when available for protection in case of damaged/exposed wiring.
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Avoid burial under trees/plants with invasive root systems that could infiltrate the cord.
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Inspect often for any exposed sections of cord due to erosion or shifting soil. Re-bury as needed.
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Carefully uncover buried cord during any future digging projects to avoid cord damage.
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Limit load to the rating of the cord and disconnect when not in use.
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Replace aging cords, ideally every 5-7 years or if cracked, worn, or damaged.
Following burial guidelines carefully and continuing safety checks will allow safe, long-term use of underground extension cords.
Burying cords properly takes some initial effort but pays off in enhanced safety and aesthetics for outdoor power access. By selecting the right burial-rated cord, digging an adequate trench, carefully installing the cord, and completing the burial with caution tape/markings, you can safely run power to detached buildings, landscape lighting, tools, and more while keeping your yard tidy. Adhering to electrical codes and using common sense precautions when burying and utilizing outdoor extension cords will provide the safest setup for your needs.