Borehole Pump

[Richard]

Hi again,

The farmer who rents land off me came round earlier with a borehole pump (i'd never seen one before..)

he'd picked it up from somewhere. Anyway he wanted to know wither it was three phase or not...? No plug on the end, just 4 wires Earth, Red, Black and I think blue.

Do these things tend to be three phase? and it is even worth me geting involved with (considering i won't be making much on it)

I couldnt see any markings on it to suggest it was three phase, although i'm guessing this would be at there would be no need for the neutral...

Model details are as follows:

Manufacture: Groundfos (SP5A-1)
No: 9037
PL: 05001512
Q: 5 m3/h
N: 2830 m-1
H: 46 N
P: 1.1kw

Also, what is the general principal? I'm envisaging a hole in the middle of a field with this pump dumped down it! is this somewhat accurate?!

Sorry i'm vaige, I only had the chance to have a glance at it, and around my way there isn't much oppertunity to work on three phase!


Rich

Thank you in advance

 

[malcolmsanford]

Unfortunately the 1.1 KW can be either 230 or 400 volts. Have a good look as there should be an indication of it. As its so small I would imagine if it is 3 phase it would be just a DOL starter, and not star/delta so you would expect just 3 cables.

Again as it is a pump if it was 230 volts you would expect 3 cables as it would have a run and start/winding. But if it was single phase I would have expected a couple of capacitors for start/run, just becasue they are not there don,t mean to say that they are not needed.

If your able you can test the windings with an ohm meter, if its 3 phase you will get the same or roughly the same reading between blue/red blue/black red /black , if it is single phase then you will get a big difference between say red/blue black/blue.

A bore hole pump is just that. Im use to slightly larger ones here in Saudi, but you normally bore down to the water table and sink the pump down until it is in the water, we use a crane and you flange your pipes onto first the pump casing and onto each pipe until you have a nice bit of pipe sticking out of the ground where you normally put a wheel valve onto it. You should also have some sort of supporting sleeve at ground level as there can be quite a lot of weight depending on how many lengths of pipe you install, which are normally always stainless. Then from the wheel vlave you can run normal galv or even PVC pipe. The biggest problems with the job is the cable joining, most pumps fail becasue of the joints in the cabling.

Now again it is not just as easy as sticking it down a hole and start pumping you will notice you will have a value of5m3/h which is head that the pump will deliver. If your water table is to deep or even not deep enough it will not take the head, and you will overload the motor as it will take high amps. The N denotes the degree of corrosion resistance.

Ive not done any in the UK but here in Saudi becasue the water table now is so low the water is coming out of the ground at nearly 72c, which is hotter than bath water, this also drasically reduces the pumps life.

So the best thing to do IMO is get a compmany in that specialise in this, it is art form designing a bore hole system

 

[Richard]

Thats a great reply, thank you for that.

I will drop in and see him tommorrow and test as you say.

Muchos gracias

 

[geofff]

If you have a look at this pdf, you will probably get info overload on grunfos pumps, page 78 gives cable csa for given pump rating.

 

[Guest123]

Does the pump itself have another flex coming out of it with a rattley ball shaped object (float switch) on the end of it???

If so the 3 cores could be N/O & N/C connections via the float switch to bring the pump in & out when the water level goes above/below a certain level???

 

[Richard]

Does the pump itself have another flex coming out of it with a rattley ball shaped object (float switch) on the end of it???

If so the 3 cores could be N/O & N/C connections via the float switch to bring the pump in & out when the water level goes above/below a certain level???

From memory, no. Just a flex from the motor to what was like a joint(?) and from there to where the plug would have been.

I will take a photo and look in more detail tommorrow.

Thank you