Obtain the necessary permits from your local municipality officials before running an underground cable from your house to a pond. They will supply you with the applicable building codes and also identify the position of underground utilities running to the house. Hire a certified electrician to install a dedicated ground fault interrupter-controlled circuit on your main electrical panel, with a conduit encased type UF cable running to the outside of the house facing the pond. Ask him to install a downward facing conduit elbow to the outside wall, with enough cable protruding from the conduit to reach the pond.
Mark the position of your trench with a can of aerosol chalk. Roll out a layer of plastic sheeting over the lawn beside the proposed trench to hold the sod and waste soil. Remove a strip of surface sod with a trenching spade and lay it on the plastic sheet. Dig a 24-inch-deep trench from the side of the house to the pond. Place the dirt on the plastic sheet and discard any rocks that you happen to dig out.
Glue a wide 90-degree conduit sweep onto a length of PVC conduit with PVC cement. Lay the end piece on the lawn, starting at the house end. Place as many lengths of conduit needed to reach the pond beside the trench. Connect the lengths of conduit together with female conduit couplings and PVC cement as directed in the written instructions.
Cut the last piece of conduit to the required length with a conduit tube cutter. Attach a second 90-degree sweep to the end piece with the outlet facing the same way as the first sweep; this will form a long flat U-shaped length of conduit reaching from the side of the house to the pond.
Place the length of conduit into the trench with the end sweeps facing upward. Measure the distance from the top of the house-end sweep to the downward facing elbow protruding from the side of the house. Cut a length of conduit to size and attach one end to the sweep with a female coupling and PVC cement.
Cut a second length of conduit long enough to fit into pond-end sweep and protrude 12 inches above the ground. Attach this piece to the sweep with a female coupling and PVC cement.
Strip off 6 inches of insulation from the ends of the UF cable with a suitable wire stripper. Thread a metal fish tape through the conduit from the pond end. Bend the end of the stripped cable and bare copper earth wire in half and secure it firmly to the end of the fish tape. Have a helper feed the cable into the house end of the conduit while you pull the fish tape through from the pond end of the conduit.
Attach the upward facing length of conduit to the downward facing elbow from the house with a female conduit coupling and PVC cement. Take up the slack by pulling the cable from the other end while doing so.
Shovel a 6-inch layer of dirt into the trench on top of the conduit and tamp it down.
Punch a hole through the bottom of a half-gallon coffee can. Thread the wire and conduit through the hole and push the can down until it rests against the 6-inch layer of dirt in the trench. Place a sheet of plywood next to the end of the trench. Use it to mix up sufficient premix concrete with water to fill the coffee can. Fill the can; tamp the concrete down and allow it to set. This will anchor the conduit and allow you to safely attach an outdoor receptacle to the end.
Roll out a layer of brightly coloured plastic electrical caution tape on top of the buried conduit. Fill the trench with the dirt removed earlier and tamp it down. Lay the strips of sod on top, tamp the sod down level with the lawn and water lightly with a garden hose.
Follow the written instructions and install the necessary waterproof junction box or outdoor electrical socket onto the end of the conduit protruding from the ground. Take special care to attach the bare copper earth wire to the side of the receptacle with the green earth nut provided.
Most 90-degree conduit sweeps have one flared end resembling a female coupling, so you only need one extra female coupling per sweep.
Tips and warnings
- Most 90-degree conduit sweeps have one flared end resembling a female coupling, so you only need one extra female coupling per sweep.