pressure switch for water storage tank

[notrub]

I would like to install a 1000L tank  3 meters higher than my house and supply well water by gravity feed.  I would like to use a ball cock on the feed pipe to stop filling the tank and I would like to turn off my submersible pump by a pressure switch that will shut off the electric feed.  I see lots of these switches in lazada that are rated 10 amp. and are priced at about 500 baht,   The pump is 1 1/2 HP and fed by a 1.5mm3 wire pair.  I understand that the running of these pumps draws low amps but the start up draws a lot.  One switch is rated as below

  Non-inductive current: 10A, full load current: 8A, and instantaneous current: 72A;When rated voltage is 250VAC

would this device work as a shut off for my pump?  Thanks for any comments.    

[lopburi3]

You do understand that you will have almost no water pressure in your house doing this?  Believe using a normal storage tank/pump would be much better.  

[Crossy]

That switch should be fine on a 1.5 horse pump.

 

You do need to consider that a 3m head likely won't trigger your water heater or produce an acceptable (cold) shower.

 

Install a ground level tank and spend the money you save on the tower on a decent pump to supply the house.

 

[Crossy]

Why not use a level switch in the tank rather than a ball valve, that would mean the well pump only starts when the tank gets to (say) 30% and then fills to full.

 

Switch ratings are typically similar.

 

Our 2-float level switch directly controls a 2HP pump that fills the tank from the river.

 

https://www.aliexpress.com/item/32682839181.html

 

 

[sometimewoodworker]

36 minutes ago, Crossy said:

You do need to consider that a 3m head likely won't trigger your water heater or produce an acceptable (cold) shower.

humm. Our house ready use tank that is at about 3m above the shower heads and during a power cut it has enough pressure for a (cold ish 25C ) shower that is certainly not great but OK enough. To be sure all the pipes are 32mm PPR up to the shower and all bends are 45 degrees and that helps. 

 

I've just done a test, the hand shower is anemic but the rain shower is better, certainly the heater can't trigger.

 

of course with the pump switched on the flow is much better and the heater triggers these are the pumped versions, the rain shower looks similar but is certainly better.

 

 

So depending on your power supply there is a case for a high level tank. 

[carlyai]

humm. Our house ready use tank that is at about 3m above the shower heads and during a power cut it has enough pressure for a (cold ish 25C ) shower that is certainly not great but OK enough. To be sure all the pipes are 32mm PPR up to the shower and all bends are 45 degrees and that helps. 
 
I've just done a test, the hand shower is anemic but the rain shower is better, certainly the heater can't trigger.

 
of course with the pump switched on the flow is much better and the heater triggers these are the pumped versions, the rain shower looks similar but is certainly better.

 
 
So depending on your power supply there is a case for a high level tank. 

Or a genset and a low level tank.

I've had the high level tank, but for me a low level tank with a couple of float switches, a bore pump and house pump and lots of filtration works best.

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[notrub]

Thank you for taking your time to reply.  We have town water to our property for garden and shower too.  The showers work OK with the pressure from the town.  The main reason we have a well is to hopefully have drinking water that is better quality that the large bottled water we now buy at 10 baht per.  (Also get rid of the water dispenser tipper thing in the kitchen)  I was thinking of gravity feed as my friend has so much trouble with his pump, although I have another friend who has trouble free experience.  Really the well will feed one tap in the kitchen having passed through a filtering process.  I do want more than a dribble so I hope 3 M is enough.  My friend has 'Big Blue' 3 filter but is not reverse osmosis.  Comments?  Thanks for the OK on the pressure switch Crossy.

 

I am taking the water to a testing lab in Buriram to see if it has poisons from the rice fields in the area.  I saw on  FB 'rural life thailand' that some people use paraquat which is legal in Thailand.  But don't know what they use here in Ban Mai Chaiyapot (Buriram Isaan).

 

Our borehole well is almost 40 M deep with water starting at 17 M.  I put 24 M of pipe for now but can easily go deeper if needs be.  I only put 24 to allow another almost 10 to lift to the top of the tank.  The pump supplier said it could lift water 40 M. 

 

Thanks again for taking an interest in my little project.  Really helpful.

[lopburi3]

First step is getting that water checked - you do not want to use bad water for drinking.  As for filter would always use RO myself - normal filters are more for taste issues and water that is, or has been treated, to safe levels.  Suspect that RO would make the town water OK without the well.  Not sure but suspect RO would require more pressure than tower tank provides (but have not researched or used on low pressure - such units are normally 4-6 stage filters so a lot of blockage).

[sometimewoodworker]

1 hour ago, notrub said:

Really the well will feed one tap in the kitchen having passed through a filtering process.  I do want more than a dribble so I hope 3 M is enough.

As long as you take on the advice to get the well water checked and you do not try to filter after the tank you will have no problems on supplying your kitchen tap.

 

 I've just done a test on a 1.5 litre water bottle unpumped it took 57 seconds vs 17 when the pump was on.

 

But you filter needs to be AFTER the pump so if you filter after your tank you probably don't have nearly enough pressure.

[carlyai]

@norub I think your best move is to have the water tested as you say. If you do a comprehensive test, then you know what type of filters to install.
Bear in mind that testing the water completely may require 6 large 1.5 L bottles and cost B6000. That's the price I was quoted at the university testing facility in khong kaen.

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[4evermaat]

On 9/29/2019 at 4:08 PM, lopburi3 said:

You do understand that you will have almost no water pressure in your house doing this?  Believe using a normal storage tank/pump would be much better.  

 

On 9/29/2019 at 5:29 PM, Crossy said:

That switch should be fine on a 1.5 horse pump.

 

You do need to consider that a 3m head likely won't trigger your water heater or produce an acceptable (cold) shower.

 

Install a ground level tank and spend the money you save on the tower on a decent pump to supply the house.

 

 

How high above the shower head/faucet does a water tower need to be to be used by itself (without a pump)?

 

Are we assuming the water goes to the ground level (or below ground) and then is re-piped through the house?

[lopburi3]

It is about 1.45 PSI per meter height.   So perhaps 25 meters higher than tap for very good water pressure of about 35 PSI.  We are assuming direct fall.

[notrub]

Thank you again for your many replies and helping me to understand about gravity fed water supplies.  I am convinced now that the best solution will be to install a constant pressure type electric pump from my ground level water tank.  My well is about 30 or 40 M from my house.  So, I can put the 1000L tank behind my house fed by my submersible pump and then hook up a second pump beside the house to provide water and will have enough pressure to pass through a filtering system and arrive inside with more than a dribble.

 

The two main brands of pumps I see are Hitachi and Mitsubishi, would anybody care to recommend which brand and model please?

 

I am going to get the water tested before spending any more money on this, however.

 

Thanks again folks.  This forum has helped me out many a time.

[sometimewoodworker]

4 hours ago, notrub said:

Thank you again for your many replies and helping me to understand about gravity fed water supplies.  I am convinced now that the best solution will be to install a constant pressure type electric pump from my ground level water tank. 

That is the most common solution and the one we had until building our new house. 

 

The problem you have have is that if you have no power you have no water, that is why in our new house we have main storage at ground level 7.5kl and an immediate use tank (1kl) at 3 ish metres.

 

We have power cuts ranging from a minute to several hours, so the high tank can always supply water. After living here it is so much better to always have water for a shower and always be able to wash off the soap, we got caught soaped up a few times when the power went in the old house.

 

 

[lopburi3]

On 9/30/2019 at 9:18 AM, notrub said:

We have town water to our property for garden and shower too.  The showers work OK with the pressure from the town.

All he needs is ability to select town water when power fails.  No needs for any tower.

[sometimewoodworker]

46 minutes ago, lopburi3 said:

All he needs is ability to select town water when power fails.  No needs for any tower.

With us the village water supply is also good (until it isn't) in the last year there have been 3 times it was cut once was for 3 weeks. We didn't know until our next door neighbour ask if we needed a water delivery.

 

So even in the case of strong supply our setup means that unless there is an interruption of over 6 weeks we won't notice or have to conserve water.

 

The other incidental benefit is that the water has time for sediment to clear.

 

again TIT YMMV.

 

[lopburi3]

5 minutes ago, sometimewoodworker said:

So even in the case of strong supply our setup means that unless there is an interruption of over 6 weeks we won't notice or have to conserve water.

You must not use much water as that 8.5k liters would not last use more than 5 days as use about 1.5k per day.  This months bill was low at 42 K units (today).  

[bankruatsteve]

1 hour ago, sometimewoodworker said:

The problem you have have is that if you have no power you have no water, that is why in our new house we have main storage at ground level 7.5kl and an immediate use tank (1kl) at 3 ish metres.

Getting a shower is the least of my concerns when the power goes out.  Which is why I have a generator that can handle the fridges, freezer, AC, fans, lights, and toaster.  Oh, and the water pump.  ????

 

[sometimewoodworker]

2 hours ago, lopburi3 said:

You must not use much water as that 8.5k liters would not last use more than 5 days as use about 1.5k per day.  This months bill was low at 42 K units (today).  

We are getting the amounts correct? 15k litres per day is about average for 8~15 people. There are two of us.

The usual billing unit is 1 cubic metre so are you using 42,000 cubic metres per month? or is there a miscommunication or misunderstanding, and you ment 42 k litres ???? 

 

42 units would seem to be around the consumption of 10 people at about 150 litres per person per day.

[lopburi3]

mis - using 1.5k liters per day - using 42 units lat month - each unit 1K.  No not 42K units.  That would be a bit excessive even for Thai bathing.  ????

 

We do have extended family so normally 8 of us using.

[sometimewoodworker]

17 minutes ago, lopburi3 said:

mis - using 1.5k liters per day - using 42 units lat month - each unit 1K.  No not 42K units.  That would be a bit excessive even for Thai bathing.  ????

 

We do have extended family so normally 8 of us using.

That's rather more reasonable, you're a bit above or high average consumption around at 175L we are a bit under so the 85,000 litres storage for 2 people is about 40+ days without conservation.

 

the Australian numbers are 100L average to 200 high average 

 

We are lucky that our water is around 4 Baht a unit so much lower than the national figures.