Submersible pump questions

[bankruatsteve]

My 2nd jet pump in 10 years crapped out the other day.  I think the same reason as the first:  ants getting into the motor.  I'm thinking of switching to submersible but confused about the options and what I would need.

 

FYI: the bore hole is 25-30m to the bottom. (won't know for sure until I extract the jet pump pipes).

The water level varies but guessing between 15-20m from ground level.  The bore casing ID is about 10.5cm so that should take up to a 4" pump, right?  Would 3" be better to avoid potential kinks in the bore?

 

"Googling" various pump specs, it looks like 1/2 HP would give me the flow I would need (mostly just to water the garden and lawn sprinklers).  Outside of head and flow rate specs, what factors should I consider in pump selection?

 

What are the "control box(s)" for?  Why do some pumps not come with control box?

 

The pumps I have looked at on Lazada do not have internal auto pressure switch.  It seems they are either on or off and external (above ground) pressure switch would be needed for that control.  Is that the case for all submersible pumps or are there brands that have internal control switch?  IE: when I turn off a connected faucet, I want the pump to stop pumping.

  

Most of the pumps connect to 1-1/2" pipe.  Should the pipe be PVC or some kind of flexible tube?  And how should they be attached at the top?  IE: what kind of additional gear should I be looking at?

 

Cheers

 

 

 

[shaemus]

2 hours ago, bankruatsteve said:

 The bore casing ID is about 10.5cm so that should take up to a 4" pump, right?  Would 3" be better to avoid potential kinks in the bore?

i would not attempt to put a 4" pump down a 4" pipe, as you correctly say your bore could be wonky or a small stone could wedge your pump in.

2 hours ago, bankruatsteve said:

 

"Googling" various pump specs, it looks like 1/2 HP would give me the flow I would need (mostly just to water the garden and lawn sprinklers).  Outside of head and flow rate specs, what factors should I consider in pump selection?

 

What are the "control box(s)" for?  Why do some pumps not come with control box?

The control box may contain the start/run cap, i have a control box with overload contactors etc in which was 5000Bht

2 hours ago, bankruatsteve said:

 

The pumps I have looked at on Lazada do not have internal auto pressure switch.  It seems they are either on or off and external (above ground) pressure switch would be needed for that control.  Is that the case for all submersible pumps or are there brands that have internal control switch?  IE: when I turn off a connected faucet, I want the pump to stop pumping.

you  would be best to pump into a tank, and then pump into your house

2 hours ago, bankruatsteve said:

  

Most of the pumps connect to 1-1/2" pipe.  Should the pipe be PVC or some kind of flexible tube?  And how should they be attached at the top?  IE: what kind of additional gear should I be looking at?

 

thin pvc with bell ends will suffice, glued well ideally with primer male thread into the pump and you can buy a male male spigot with a plate to sit over the bore. add a rope to the submersible pump nylon or stainless wire so you can pull it out not using the pipe and also to suspend the pump off not the pipes. if you need to service the pump

2 hours ago, bankruatsteve said:

 

Cheers

i am now way an expert on bore pumps, i am using a cheapish chinease pump i bought at homepro. you are not pump very high or for extended lengths of time so a Grundfos might be overkill. you show add some float switches to your "bladder tank" high low.

 

Also the pumps available in Thailand never seem to have the earth connected and the splice kits used in my opinion are rubbish. You should look out for pre glued heat shrink (online) and a correct type of cable suitable for submersion

[bankruatsteve]

I already have a tank and pressure pump for the house with village main sufficient to fill the tank.  As mentioned, the bore hole would only be used for watering the garden as the village main usually not enough pressure.

 

So, the submersible pumps don't have pressure control in the pump?  I will need separate control box on the output?  Are the "Home" places likely to have all the kit I will need to hook into the system I had with the jet pump?

 

Thank you.

[Fruit Trader]

This thread need cheering up with a Buriram pic.

 

[sometimewoodworker]

1 hour ago, Fruit Trader said:

This thread need cheering up with a Buriram pic.

 

How about an off topic Ming Moll picture or 2 from my favourite engineers educational videos  “Down There”

the gratuitous Molls start at 7:55

 

 

 

Edited April 25, 2020 by sometimewoodworker

[KhunBENQ]

9 hours ago, bankruatsteve said:

So, the submersible pumps don't have pressure control in the pump?  I will need separate control box on the output?  Are the "Home" places likely to have all the kit I will need to hook into the system I had with the jet pump?

We have a 3" pump in 4" bore hole, 0.5 HP, 1" output diameter.

About 30m deep. PVC tubes each about 4m long with thread (no teflon seal used).

The pump has no pressure control. As almost all small pumps it's a single phase motor. So of course a "control box" aka. capacitor needed.

There seem to be motors with integrated capacitor, NOT recommend.

The capacitor is a potential wear part, cost about 300 Baht for such a small motor.

The pump cost around 7000 or so incl the box and 50m electrical cable.

A DoHome own-brand. DoHome is one of the less frequently seen big stores.

Works fine since May 2016.

For "hanging" the motor the shops here now offer outdoor telephone cables (what hangs on the poles). Very sturdy/resistant.

I also recommend to use another cheap tank to fill up.

We use the water to fill the tank feeding the house water pump.

 

Edited April 25, 2020 by KhunBENQ

[KhunBENQ]

What did not work out fine: the adaptor on top of the borehole.
Recently shocked that no water comes up just a gargling sound from "below".

 

The culprit and it's replacement:

 

 

Edited April 25, 2020 by KhunBENQ

[bankruatsteve]

3 minutes ago, KhunBENQ said:

I also recommend to use another cheap tank to fill up.

Well, then I would need space for another tank and buy another pump (just to water the garden).  Maybe I'll just get another pressure activated jet pump and figure out how to keep the ants away.  I wonder why the submersible pumps are so expensive if they are so dumb.  (?)

[Mama Noodle]

On 4/24/2020 at 1:21 PM, bankruatsteve said:

The bore casing ID is about 10.5cm so that should take up to a 4" pump, right?  Would 3" be better to avoid potential kinks in the bore?

 

You CAN put a 4" submersible pump in a 4" well bore as long as the ID of your well is actually 4". 4" pumps are designed to fit in a 4" hole. They are typically around .25 or more smaller. a 4" sub pump is usually something like 3.750" in diameter. You can buy a cheap caliper to check the measurements of the pump before buying it. 

 

On 4/24/2020 at 1:21 PM, bankruatsteve said:

"Googling" various pump specs, it looks like 1/2 HP would give me the flow I would need (mostly just to water the garden and lawn sprinklers).  Outside of head and flow rate specs, what factors should I consider in pump selection?

 

There is quite a bit of calculation that goes into pump selection and the flow rate is only a small part of it. You need to figure out your desired pressure range, the pump 'head' and your max desired usage. Typical household pressure is around 35 psi. I prefer mine a little higher at about 40 psi. 

 

On 4/24/2020 at 1:21 PM, bankruatsteve said:

What are the "control box(s)" for?  Why do some pumps not come with control box?

 

Submersible pumps don't know when to start or stop so you have to buy a pressure switch to control them. Thats the 'control box'. Sub pumps generate a hellatious amount of INSTANT pressure so there are auxiliary parts that have to go along with them. 

 

On 4/24/2020 at 1:21 PM, bankruatsteve said:

The pumps I have looked at on Lazada do not have internal auto pressure switch.  It seems they are either on or off and external (above ground) pressure switch would be needed for that control.  Is that the case for all submersible pumps or are there brands that have internal control switch?  IE: when I turn off a connected faucet, I want the pump to stop pumping.

 

No, they typically are not to be used in that way due to the incredible amount of instant pressure they provide as soon as they get voltage. A proper system utilizes 4 basic parts:

 

Pump - Pressure Control Switch - A bladder tank or diaphragm tank - and an overpressure relief valve. 

 

On 4/24/2020 at 1:21 PM, bankruatsteve said:

Should the pipe be PVC or some kind of flexible tube?  And how should they be attached at the top?  IE: what kind of additional gear should I be looking at?

 

PVC is ok but in the states its all black iron pipe with a rubber buffer. When the pump kicks on it has quite a bit of torque so insulating that force from the plumbing means you'll get more life out of the system without having to mess with it. 

Its my opinion that the outlay for a proper system that a person would be satisfied with is just not worth it compared to just replacing an old jet pump and most locals would have absolutely no idea how to work on such a thing. 

[Mama Noodle]

Ive thought long and hard about doing a sub pump system for my house and my main motivation was lowering my electrical usage. A 4" well and correctly sized pump can easily supply a whole house, garden, and whatever else without the need for a storage tank nor several auxiliary pumps but the outlay is a bit hard to swallow. 

[Mama Noodle]

43 minutes ago, bankruatsteve said:

I wonder why the submersible pumps are so expensive if they are so dumb.  (?)

 

They aren't dumb at all, in fact its the water system that the Thais use that is actually kind of 'dumb'  but in reality the reason it is the way it is here is because most locals can't afford the outlay or complication of a submersible pump system. Remember, a sub pump and pressure tank completely removes the need for multiple pumps and storage tanks, uses less overall power, and provides immense water volume constantly. 

[bankruatsteve]

41 minutes ago, Mama Noodle said:

 

They aren't dumb at all, in fact its the water system that the Thais use that is actually kind of 'dumb'  but in reality the reason it is the way it is here is because most locals can't afford the outlay or complication of a submersible pump system. Remember, a sub pump and pressure tank completely removes the need for multiple pumps and storage tanks, uses less overall power, and provides immense water volume constantly. 

Not at all trying to argue with you... From what I see, the "control box" that comes with a pump couldn't respond to pressure since there is no connection to the pipe.  Or, does it do that based on Watts being pulled?  A seller in Lazada referred me to a pressure switch (see attached photo) if I needed pressure cut-off.  

 

Can you link to the type of pressure tank you talk about?  Again, I don't need immense water volume constantly - only when water the garden.

 

Thanks.

[Fruit Trader]

59 minutes ago, Mama Noodle said:

 

They aren't dumb at all, in fact its the water system that the Thais use that is actually kind of 'dumb'  but in reality the reason it is the way it is here is because most locals can't afford the outlay or complication of a submersible pump system. Remember, a sub pump and pressure tank completely removes the need for multiple pumps and storage tanks, uses less overall power, and provides immense water volume constantly. 

Just curious.

 

Why is the water system the Thais use kind of dumb?

 

What do the poor locals fit on the end of submersed well pumps if the pressure tank system is too expensive?

[Mama Noodle]

14 minutes ago, bankruatsteve said:

Not at all trying to argue with you... From what I see, the "control box" that comes with a pump couldn't respond to pressure since there is no connection to the pipe.  Or, does it do that based on Watts being pulled?  A seller in Lazada referred me to a pressure switch (see attached photo) if I needed pressure cut-off.  

 

Can you link to the type of pressure tank you talk about?  Again, I don't need immense water volume constantly - only when water the garden.

 

Thanks.

 

Can you show me what control box you are referring to? Theres kind of 2 or 3 ways to run these things and I believe the one you refer to is using pump load instead of real pressure 

 

A pressure tank like this but keep in mind I am only showing the design and not looking at price or size. 

 

https://www.lazada.co.th/products/50-pressure-tank-50-litre-bauman-100-i408062186-s792664944.html

[Mama Noodle]

10 minutes ago, Fruit Trader said:

Just curious.

 

Why is the water system the Thais use kind of dumb?

 

What do the poor locals fit on the end of submersed well pumps if the pressure tank system is too expensive?

 

Not sure what you're trying to ask me but why buy an expensive pump and run cheap parts to utilize it when a jet pump is cheap as heck and will provide the same water. 

 

Only exception being very deep wells where a sub pump is necessary. 

[Fruit Trader]

3 minutes ago, Mama Noodle said:

 

Not sure what you're trying to ask me but why buy an expensive pump and run cheap parts to utilize it when a jet pump is cheap as heck and will provide the same water. 

 

Only exception being very deep wells where a sub pump is necessary. 

I am asking you to provide a little more detail from your post #13

 

 

Why is the water system the Thais use kind of dumb?

 

What do the poor locals fit on the end of submersed well pumps if the pressure tank system is too expensive?

[Fruit Trader]

39 minutes ago, bankruatsteve said:

Not at all trying to argue with you... From what I see, the "control box" that comes with a pump couldn't respond to pressure since there is no connection to the pipe.  Or, does it do that based on Watts being pulled?  A seller in Lazada referred me to a pressure switch (see attached photo) if I needed pressure cut-off.  

 

Can you link to the type of pressure tank you talk about?  Again, I don't need immense water volume constantly - only when water the garden.

My advice to you would be replace your jet pump.

 

Video is typical well pump arrangement in the US. Its nothing more than a bigger version of your existing house pump. You could of course just pump into a big tank like we do on the farm.

 

 

 

 

 

 

 

 

[Mama Noodle]

8 minutes ago, Fruit Trader said:

Why is the water system the Thais use kind of dumb?

 

Because its a hodge podge of parts put together that's extremely inefficient typically using several different pumps and tanks when just one system can be used. 

 

I already addressed the reason they do what they do in post #13

 

 

[Mama Noodle]

3 minutes ago, Fruit Trader said:

My advice to you would be replace your jet pump.

 

I would agree in OP's case, but there is something to be said for it as with a sub pump & pressure tank you can completely do away with multiple auxiliary pumps and storage tanks. 

 

4 minutes ago, Fruit Trader said:

Video is typical well pump arrangement in the US. Its nothing more than a bigger version of your existing house pump.

 

Thats not true at all, a house pressure pump operates completely differently than a submersible pump and pressure tank. 

[Fruit Trader]

1 minute ago, Mama Noodle said:

 

Because its a hodge podge of parts put together that's extremely inefficient typically using several different pumps and tanks when just one system can be used. 

 

I already addressed the reason they do what they do in post #13

 

 

Yes we do that. A 20000 Baht deep well pump into  10000 L storage.

 

A bladder tank and pressure switch would be a lot cheaper.

[Fruit Trader]

1 minute ago, Mama Noodle said:

 

I would agree in OP's case, but there is something to be said for it as with a sub pump & pressure tank you can completely do away with multiple auxiliary pumps and storage tanks. 

 

 

Thats not true at all, a house pressure pump operates completely differently than a submersible pump and pressure tank. 

Explain why the house pump is different besides maybe a lower pressure and volume.

[Mama Noodle]

Just now, Fruit Trader said:

Explain why the house pump is different besides maybe a lower pressure and volume.

 

A house pump, the one the kicks on when you open a tap, utilizes a bypass type of valve assembly with a mini bladder tank that creates a steady water pressure at different required water volumes. The pump runs ALL THE TIME when a valve is open. 

 

A sub pump (a typical design) uses a pressure tank and pressure switch. When water pressure drops below a certain point the pump kicks on (for example 35PSI) and kicks off when high side pressure is reached (55 or 60 PSI). The bladder tank provides water pressure/volume storage so that the pump RUNS LESS OFTEN. Meaning you can flush toilets/wash hands etc without running the pump at every instance. 

 

If running a 1/2 HP or 1 HP electric motor every time you open a tap sounds good to you and your electric bill - by all means go for it. 

[Fruit Trader]

12 minutes ago, Mama Noodle said:

The pump runs ALL THE TIME when a valve is open.

Not if the demand is below pump capability. It will cycle on the pressure switch differential just like a well pump and bladder tank does.

 

Pump + pressure switch + bladder tank big or small its the same principal. Add flow detection and you have constant pressure control. 

 

Some pics to help.

 

 

 

 

 

Edited April 25, 2020 by Fruit Trader

[CGW]

2 hours ago, bankruatsteve said:

Well, then I would need space for another tank and buy another pump (just to water the garden).  Maybe I'll just get another pressure activated jet pump and figure out how to keep the ants away.  I wonder why the submersible pumps are so expensive if they are so dumb.

I use a submersible that I have hooked up to a sprinkler system to water the garden, to turn on/off I use the float switch in a separate tank which is only used for watering garden, been working well that way for over five years now. You could use a float switch to turn on off without the tank, though would obviously be "manual"

[Mama Noodle]

15 minutes ago, Fruit Trader said:

Some pics to help.

 

Those 2 pumps are completely different from one another in their design and incomparable to each other other than they have the same 'parts'. 

 

The difference that you don't seem want to understand is that they operate with different valve assemblies and use their parts in a different design. 

 

Just because something has a pressure tank and a switch and a valve does not mean it's the same thing or that it operates in the same way. 

[Fruit Trader]

18 minutes ago, Mama Noodle said:

 

Those 2 pumps are completely different from one another in their design and incomparable to each other other than they have the same 'parts'. 

 

The difference that you don't seem want to understand is that they operate with different valve assemblies and use their parts in a different design. 

 

Just because something has a pressure tank and a switch and a valve does not mean it's the same thing or that it operates in the same way. 

The control principal is the same so stop drifting off into pump design and valve assemblies.

 

If you dig yourself any deeper you'll be needing a pump to prevent drowning.

 

I will spare you the expense.

[Mama Noodle]

52 minutes ago, Fruit Trader said:

The control principal is the same so stop drifting off into pump design and valve assemblies.

 

If you dig yourself any deeper you'll be needing a pump to prevent drowning.

 

I will spare you the expense.

This is as dumb as saying an 18 wheel tractor trailer is the same as a Honda city because they both have engines and transmissions and driveshafts and wheels therefore they are the same thing. 

[tweedledee2]

Just completed drilling a well on Tue: 39m deep, 4" casing and 3" submersible pump. Father and son team started drilling on Mon. just before 3pm and were at 15m at 5pm. Returned at 7:30am the next day, drilled the final 24m and finished the installation at about 3:30. The male and female threaded connectors were glued to each section of pipe, then secured with 2 ss screws. 5/16" nylon rope was used to lower the pump and the first pipe section. The power cable and rope were secured to each section of pipe, then the rope was looped 3x around the pipe just below the female fitting, before the next section was fitted. Teflon tape was used on all the male thread connections. The 1-hp ss and bronze pump with controller was Mitzan brand. Total cost 17,000 baht. 

[bankruatsteve]

1 hour ago, Arjen said:

As a side node, what do the abbreviations PSI and HP mean? 

PSI = pound-force per square inch,  HP = horse power

 

My issue with using a sub-pump to fill a tank and then using another pump to take it out of the tank for the single purpose of watering the garden just doesn't make sense to me.  When I water the lawn, I have 3 stations where i run a sprinkler for 20 minutes each (1 hour total).  But, every 20 minutes I need to turn off the faucet and move the sprinkler to the next station.  I don't need the pump to keep pumping during the off time and maybe bursting pipes.  Similarly, my wife will use a nozzle on the hose to constantly start/stop the water when she waters her garden.  The 1-1/2 HP jet pump was just fine for that purpose.  The sub-pump seemed like it would be more efficient and not susceptible to the ants but maybe not the best solution for my application.

[bankruatsteve]

What do you motor guys think about this:

 

When I plug in my jet pump it just buzzes.  Previously when it did that, I would manually spin the fan and the pump would start as normal.  Now, when I manually spin the fan, it rotates very slow (guessing 30 rpm) and the power cable starts to heat up.  The pump does nothing.

 

Opening the cover, I find a 25 µF cap which looks OK.  Removed and measured on my DMM where it leveled out at 18.4.  Is it likely this could be the problem?  The previous pump had the winding shorted by the ants and was toast according to the fix-it guy.