I have a 3 phase borewell with 2.5inch water pipeline spread across my farm. Due to some reasons, the electricity in the area is only being served as single phase in last one month.
My plantations are suffering and I have decided to draw water from the open well and river along my farm and provide for some water to the plants till it starts raining.
Kindly suggest me a single phase water pump which can draw water to one of my existing outlet in the pipe network of 2.5 inch.
Distances as given:
River to Pipe Opening: ~ 450 ft … Steady Elevation of around 10 ft
Well to Pipe Opening: ~750 ft … Almost Same elevation with minor ups and downs.
My primary motive would be to draw the water from the river.
It would be very helpful if someone could suggest;
A “SINGLE PHASE” pump suitable for option “1”
A “SINGLE PHASE” pump suitable for both option “1” and “2”
It ma not be Possible to Operate a Pumpset with the available Single Phase supply.
Because a THREE Phase supply is available to your Farm/Land, there the Neutral may not be available.
This single Phase is for the Nearby resident locations where the Neutral is available.When your Turn of THREE Phase this Single Phase supply is also considers for your Connection. Some may advise that this single Phase can be used by having Earth as Nutral. But it will not work moreover it will damage your equipment and Danger too.
single phase motors are designed for domestic uses, they can be used 1hr in a strech or may be 2hrs. 1 use a single phase motor but i dont run it more 1 hr. I use only in summer(stand by motor).
The electrician has some trick, connection is same as of 3 phase.
Farmers around me use a condenser when there is a single phase supply and make a psuedo phase, but the voltage will be drastically reduce.
May be we can adress this using VFD? I dont know
We will have this luxury only for six more months, EB is laying separate lines agri and domestic uses. There will be any single phase anymore.
We have/had this problem for more than a year. We went for single phase pump this year for our borewell.
In your case you haven’t specified how much water o/p you are expecting from the pumping system.
More over you also need to provide the distance between your electric board and the openwell/river.
The biggest problem with single phase pumps is that since the voltage is almost half of that of 3 phase, and the current is almost double as that of 3 phase, the drop in the electric cable is considerable.
As far as neutral line is considered, I think it should already be there in your 3 phase connection. Typically I have seen 4 wires running into the board from the pole. One of them is neutral. This is what I have seen, not sure if applies to you or not. And using earth as neutral is not possible.
Phase converters work if you have two phase supply. You can’t use them if you have only one phase supply.
And it is incorrect to say single phase pumps can not be used for continuous operation. Experts say most of the burning happen due to running dry or running without enough water around the motor. Three phase pumps can tolerate this condition to an extent, but single phase motors can not. This is because single phase motors generate more heat compared to Three phase one’s. As long as you make sure the whole motor-pump assembly is fully submerged in water, a single phase pump can be operated for hours without any problem.
Technically VFD can be used to convert a single phase supply to 3 phase supply, but I haven’t had success in finding a suitable product in our market. Moreover, they are too expensive for us the bear the cost (30K - 50K).
First of all you cannot have a common pump serving both cases 1 & 2, as case 1 requires monoblock and case 2 requires borewell submersible.
Option 1:
A)Have a monoblock pump to draw water from river ( which I am quite not sure is legal or not) and select a single phase pump which will draw sufficient water as per your requirement.
Have a 3m platform near the river, mount the pump on it. Select a pump with 65mm delivery size (suction size not important) which offers your required water @ 8m head.Connect the delivery of the pump to your 2.5" existing water lines
B)You have not mentioned the bore depth, water table, bore dia without which I would not be able to suggest you if single phase borewell pump would suit you or not
Option 2:
Yes like others have mentioned, you could use VFD which will convert single phase supply to three phase supply and would come with all standard motor protections like dryrun, lightning, surge, overload, overvoltage etc.The VFD’s we offer would support input 200 ~ 240Vac. But catch is output would also be 200 ~ 240Vac but three phase. Meaning you would need a low voltage motor or a stepup transformer/stabilizer rated for 415V 3phase output.
Few good to know stuff;
A)3 phase connections for farming are basically 4 wire system i.e 3 phase + 1 Neutral
B)Its a myth that single phase motors cannot run for long. Motor coil burn would be mainly because of overvoltage, overload,dryrun and motor heating whether its 3phase or single phase
C)Voltage drop or rather power drop would be more in case of single phase transmission lines than 3 phase lines because of low voltage
D)Single phase lines for pumps would need higher gauge cables as amperage would be more when compared to 3 phase lines
What you said all are Correct except THREE Phase Connection is having TREE Phases and ONE Neutral. But for the THREE Phase Agrl. Connections are not having any Neutral. The Motor will run on THREE Phases and One Earth Point. To avoid misusing of FREE Electricity, Govt have made this System/ Design, because ONE Phase will be there for round the Clock. If singl Phase is needed one should apply for another Sinle Phase Connection Sir.
I do not intent to keep replace the borewell pump. I am looking to buy a seperate backup pump to draw water from River and open well.
The Electric Supply is near the Water Outlet I mentioned so the distances for electricity remain the same as the distances mentioned for the distance to which water has to be drawn.
I need to get the motor running for 1 hour at least to feed in my drip lines spread across 2.5 acres for mango and drumstick plantation.
You need to Purchase Mono block Centrifugal Pumpset of THREE Phases. so long as the Pump is running with water flow can run any Hours. But runs in dry Stage it may burn in minutes.