Water pressure switch for water pump

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I have a 1100W water pump and a water pressure switch which fails to control it. The switch supposedly starts at 1.5bar and stops at 10bar (it is not clear when it stops, but it says "10bar, 10A". The pump can never reach 10bar, and a good thing too, and so the switch never stops it. I would like the switch to start at 1.5 bar and stop at 3bar, and without oscillations. Is there a particular brand/model I should be looking for?
 
The switch will be rated up to 10Bar pressure and a max current of 10A

What pump is it? Are you talking about say a surface or submersible kind of water pump, used for say draining basements or the like? Or are you talking about a potable well or accumulator type pump?
 
What pump is it?
I have now realised the switch/controller (WAPS002) is not possible to adjust manually, and it is set at the factory for 10 bar... I need to buy an adjustable controller.
 

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The switch will be rated up to 10Bar pressure and a max current of 10A

What pump is it? Are you talking about say a surface or submersible kind of water pump, used for say draining basements or the like? Or are you talking about a potable well or accumulator type pump?
It is a normal water pump, 1100W, intended to take water from a tank (about 900 litres) and feed it to the house. The tank is about 1.5 floor levels high and there is enough gravity pressure to run the ground floor taps, but not upstairs.

The tank is needed to alleviate water shortage related mains interruptions.

Normal mains pressure is an incredible 5 to 5.5 bar ... If water supply is switched over to the tank, I'd be happy with 2-3 bar.

I need a controller system to start the pump at about 1.5 bar and stop it at about 2.5-3 bar.

It seems the various "cheap" electronic controllers (about £50) cannot be adjusted when to stop the pump, or at all.

Therefore I realised I need a mechanical pressure switch, to adjust when it starts and when it stops the pump. And an expansion tank to smoothen the operation.

I also realised I would also need detection of "tank empty" and stop the pump when dry. I think that would then require another pressure switch, I am not sure.
 
To detect when the tank was empty you would need a float switch not a pressure switch in series with your other controls.
There seems to be several pressure switches that might meet your requirements here
 
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I want to detect "no water reaching the pump" in general, so as not to run it dry and burn it. It could be an empty storage tank, but it could also be a closed valve or a blocked filter etc.

For that I *think* I need another pressure switch to break contact at low pressure, rather than make contact.
 
Yes, you require another pressure switch that breaks at a minimum pressure, (tank head) and remakes at a pressure corresponding to a minimum tank (head) level, wired in series with the pump start/stop pressure switch, additionally, because your house demand won't be continuous? you will/should require a small accumulator to prevent the pump cycling on/off too rapidly. If, say, you have the pressure switch set 1.5bar/3.5bar, and a 50L accumulator, precharged to 1.5 bar then the accumulator will store 22L at 3.5bar and assuming a flowrate of say 15LPM the pump will not restart for 1.5 minutes in falling to 1.5bar.
You will also require a double type non return valve on the mains supply.
That seems a very big pump at 1100W for a domestic house supply, the Stuart Turner type are around 500W and will pump ~ 20LPM at 3bar depending on model chosen.
Can you post any/all details of your pump, there should be reasonable labelled info on the pump, take a note of all this info or a snapshot and post it on.
 
I have a 50L expansion tank, and have bought 2 pressure switches (in the post). I have a non-return valve at the pump input, and a 6 bar pressure valve at the pump output.



IMG_20250812_094343.jpg
 
If you are pumping into the mains then you will require that DRV, otherwise you might be supplying the whole country?
What are the pressure ranges of the two ordered PGs?

Will revert later, must go out for a few hours.
 
If you are pumping into the mains then you will require that DRV, otherwise you might be supplying the whole country?
What are the pressure ranges of the two ordered PGs?

Will revert later, must go out for a few hours.
Pumping from storage tank into house.

The pressure switches are mechanical and adjustable, from what I understand.
 
So the discharge from the pump is not teed into the mains supply in the house?
The WAPS002 just says it can withstand 10bar pressure, surprising its not adjustable and even if it isn't it should have a cut out pressure of 3.5/4.0bar. It also states it has run dry protection but the MIs don't give any info on these points.
The tank is ~ 1.5 floors height so ~ 6m, 0.6bar so your own run dry protection switch must be settable down to a very low pressure, the pressure gauges have a operating range, hope yours is suitable for this.
The pump has a deadheaded pressure of 4.6bar so you could safely set the cutout pressure to 4.0bar, will give you 25L in the accumulator and a bit more breathing space.
 

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