How to Wire a Submersible Pump

Submersible pumps are commonly used in ponds or anywhere you need to get water movement. A submersible pump used in a pond typically forces water higher than the actual water level, such as for waterfalls or fountains. Wiring is simple since it generally requires only two wired connections; submersible pumps are not often grounded. You do need to ensure that you use the correct cable and all the waterproof seals are secure.

Wire a submersible pump to circulate your pond water.
  1. Measure the distance between where the submersible pump is positioned and the power source by using a tape measure. Add a few extra feet to the measurement.

  2. Purchase dual core American Wire Gauge (AWG) 12 submersible cable from an electrical supply store. Do not use any other type of cable to wire your submersible pump. This cable is specifically constructed for underwater use.

  3. Locate the screws on the submersible pump cover. The screws may have small plastic caps on top to stop them rusting so pry the caps off using a small screwdriver then remove the screws.

  4. Lift off the pump cover and put it to one side. Inside the pump compartment is the pump motor protected by a sealed waterproof cover.

  5. Remove the screws holding the cover in place. Again, the screws are likely to have protective caps so you will have to pry them off first. Carefully lift off the pump motor cover. There is a rubber seal that goes around the cover which functions to stop water entering the motor. Check for the rubber grommet where the wire feeds into the motor and remove it.

  6. Slide the rubber grommet up the cable about 1 foot. It is a tight fit, but don't be tempted to use oil or grease to lubricate the cable or grommet.

  7. Use wire strippers and remove 2-inches of plastic off the end of the submersible cable. The outer plastic is tougher than regular cable. If you get it wrong, then cut the cable clean using a knife and start over; you allowed extra cable.

  8. Remove 1/4 inch of plastic from the two colored inner wires by using wire strippers. This reveals the copper core that connects to the pump terminals.

  9. Loosen the small terminal screws on the pump motor by using a screwdriver. Don't remove them. Check the terminal labels; one is "Hot" meaning live and the other "Neu" meaning neutral.

  10. Insert the copper core on the end of the gray or white wire under the loosened screw of the terminal labeled "Neu" and then tighten the screw. Check to ensure the wire is secure. Insert the copper core on the end of the remaining wire -- it is colored black, red or orange -- under the loosened screw of the terminal labeled "Hot" and then tighten the screw. Check to ensure the wire is secure.

  11. Slide the rubber grommet down the cable until it reaches the outer casing of the pump motor. Set the grommet in its position. Place the pump motor cover onto the base unit. Ensure the rubber seal is positioned all around the lip on the cover and the pump base.

  12. Insert the screws into the screw holes on the pump motor cover. Use a screwdriver to lightly tighten the screws. Check again to ensure the seal is in place. Tighten the screws alternately which ensures the cover gets fitted evenly. For example, if there are four screws, tighten the first and third screw then tighten the second and fourth screw alternately. Replace the plastic covers onto the screws. Push them into place using your fingers.

  13. Replace the outer pump cover. Replace the screws and tighten them. Put on the plastic covers and push them into place.

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