Lowering the pump

8. 1 LOWERING THE PUMP

The main part of the installation involves the placement of the pump. Lowering and positioning the pump requires the greatest level of coordination and effort. It can take anything from a few hours to an entire day, depending on the depth of the borehole and the number of connections.

The process consists of introducing the pump vertically into the borehole while connecting the piping. As each section of pipe is connected, the pump is lowered 3 or 6m. This continues until the installation depth is reached. The detailed process is described below:

1. If you´re using galvanised steel pipe, prepare some of the pipe sections by fixing the threaded sockets on one end, and wrapping Teflon tape or fibers on the other. The coupling will stop the pipe from falling if the clamp slips.

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2. Drive a section of steel pipe 80cm into the ground, inclined at an angle of 30º in the opposite direction of the borehole. It´ll act as a brake post to prevent the pump accidentally falling down the borehole. The steel cable is looped around it three times, which will stop it slipping in case of a fall. One person is in charge of letting the cable out as the pump is lowered.

3. Remove the pump from its box and lay it on a smooth horizontal surface, so that it´s supported over its entire length. It´s easy for the pump shaft to become deformed if not.

4. Join the submersible cable with the splicing kit if the manufacturer hasn´t already done so. Never handle the pump by pulling on this cable!

5. Pass the steel cable through the holes of the pump casing and fix 3 cable clamps, 5cm apart:

© Santiago Arnalich Arnalich. Water and habitat www.arnalich.com 6. Join the first pipe section to the pump. Take special care not to damage the

pump and don´t use any kind of tool to hold or turn it. For the join to be watertight, use Teflon tape or natural fibres. By the end of this step you´ll have the pump, with the electrical cable and the first pipe section connected.

The first pipe section is 1 meter long, to make entering the borehole easier. If the pipe is galvanised steel, screw a coupling on the end to act as a buffer.

7. Place the first omega clamp over the short pipe section, joined to the pump, with the second over the next pipe section together with the coupling. Make sure you tighten the screws properly so it doesn´t slip down the pipe.

8. Fix the cable protector clip. This is a homemade part, consisting of a small length of steel pipe 1” in diameter, 20cm long, with a clip welded on the side.

The submersible cable is passed through the middle and the clip is fixed to the inside of the borehole entrance.

Its purpose is to protect the cable mechanically. It´s very common during an

installation for the column to pinch the cable against the mouth of the borehole and damage it.

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9. Raise the pump and pipe with the crane and align it with the mouth of the borehole. The crane tends to be manual, chain operated, with a tripod. If you can afford a loader crane, it´ll speed things up.

10. Lower the pump until the clamp rests on the mouth of the borehole. Fix the submersible cable to the rising main with rubber clamp, but this time, leave the steel cable out.

© Santiago Arnalich Arnalich. Water and habitat www.arnalich.com 11. Release the crane, and let the column rest entirely on the clamp. Fix the pipe

section with the second clamp on it to the crane, and place it over the coupling at the end of the column. Thread the pipe into the column. If you have problems, use vegetable oil (i.e. sunflower or palm oil) as a lubricant.

Observe that while two people work joining the pipe, another in the foreground already has the next one ready, with a third person (sitting on the roll of rope to the right) in charge of the braking post:

12. Half way up, and at the end of each pipe section, the cables are fixed to the rising main with a rubber clamp.

13. This continues until the installation depth is reached. Once there, the borehole lid is screwed in, and the non-threaded lid is fixed in place. The steel cable is also passed through the ring on the lid and secured with clamps. Remember there are 3 things referred to as clamps: the omega shaped ones which secure the pipe, the rubber ones which secure the cable to the pipe, and the ones that clamp the steel cable to itself.

14. Remove the protection clip and pass the submersible cable through the hole in the lid, made for that purpose.

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15. Connect a small piece of pipe to the lid to lift it at. The lid doesn´t have anywhere for a clamp to fit in. The way to lower the lid into its place is to use this piece of pipe, which will then be connected to the elbow.

The lowering process can change a little, depending on the circumstances and the materials you have at your disposal, although it´ll be much like what has been described above.