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Hi,

I have dug a borewell till a depth of 500 feet and recently got the camera guy come and look into the same. The person is asking for the pump to be placed at 470 feet.

The water sources are at less than 200 feet little stones (boulders at 350 and 400 feet).

what is the right level where i should put the pump at. The deeper I put the cost of pipe and other costs are higher.

Please suggest.

Also he has recommended 2HP pump single phase 25 stage. Is this sufficient?

Well if you want to utilize every bit of water available in your well, then you should go down as deep as you can go. Secondly incase after sometime the water getting stored is below the pump height then you will not be able to utilize it. Like you get the pump installed at 300ft but water gets stored till 350ft, then 150ft of water will not get utilized . Thirdly it's more expensive lowering it later than doing it now.

Single Phase or 3 Phase pump is always a question I went through during my borewell installation process.
Advantages of Single Phase :
1. Deposit for KPTCL is less for 1-Ph
2. Does not have issues with Phase reversal
Disadvantages
1. Slightly expensive than 3-Ph pumps
2. Requires a higher sqmm cable so as to carry the current
3. Lesser efficient

Advantages of 3-Ph
1. Efficient than 1-Ph, so slightly lesser power bills.
2. Requires lesser sqmm cable. This reduces the cost of cabling. Assume you require 20A to be carried for your pump, 1-Ph requires a cable which requires 20A handling capability but 3-Ph would have 3 phases so current would get divided to 6.6A/Ph so instead of a 4sqmm cable you can opt for 2.5sqmm cable, considerable savings here.
Disadvantages
1. Requires a 3-Ph connection from KPTCL so the deposit amounts are a little higher
2. Incase KPTCL reverses the phases in the mains then the either the pump runs in reverse (In case of no protection of Phase reversal) or will trip due to electronic protection. I go through this headache sometimes.

As I understand 1-stage means it can lift water upto 20 feet. You can do the math yourself with factor of safety. Also consider the height of the overhead tank if you are directly pumping into it. Having couple of stages extra should be helpful once the pump ages.

Hi,

Thanks for the great reply...

If 1 Stage is 20 feet then 25 stage motor should be able to pump upto 500feet. I am building just G+1 house so is it too high.

So is 25 stage motor too much for this requirement.

You also need to factor in the little stones and the boulders at 200 feet and boulders at 350 feet. These would cause headaches later when lifting the motor for repair.

If there is only one water source at less than 200 feet and you are sure there are no other sources after 200 feet. In my opinion, putting a motor deep down is of very little use. The amount of water that gets stored in the bore well would be 300feet into 22/7 * r square. Where R is the radius of the bore hole. This is the amount of water you would not use.

If I were you, I would put my motor at 195 feet or so and save money and maintenance hazzles. You can go with 12 stage pump with a suitable motor.

If there are other water sources between 200 feet and 500 feet, then putting the motor at 470 feet makes sense.