Fix Underground Wiring

Repairing the cable

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Underground connector

Use underground connectors to fix a severed cable.

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Photo 1: Join the wires

Insert the wires into the connectors, making sure the colors match up, then tighten the screws.

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Photo 2: Seal the connection

Slide the heat-shrink tube over the connector. Use a heat gun to shrink it and seal the connection.

If you accidentally cut an electrical cable while digging or pounding in a fence post, you can repair it with a splice. First turn off power to the electrical device fed by the broken cable at the circuit panel. Then dig 12 in. on each side of the break in the wire and gingerly work your way to the cable. You'll find the cable anywhere between 12 and 24 in. deep. When you locate the cable, use a noncontact voltage detector to ensure there’s no power.

Replace the whole section of cable that you dug up with the same gauge UF (underground feeder) cable. Cut the cable about 12 in. on either side of the break. Then strip back the sheathing 2 in. and the wire insulation 5/8 in. Use two special underground splice kits (sold at home centers) to connect the new cable section. Slide the heat shrink tube over one end of the cable, then connect the wires to the brass connector (Photo 1). Do this on both ends of the new cable. Once the damaged cable is replaced and the wires are joined with connectors, slide the heat-shrink tube over each connector (Photo 2). Heat the tube with a heat gun until it shrinks tight on the connector and sealant bubbles out the end.

If you have a broken underground line and no clue where the break is, hire an electrician with an underground open/short locator. The electrician will be able to locate and mark the underground cable, determine how deep the cable is buried and pinpoint within a few inches where the problem exists.