random pressure drop - Booster

[KLB]

Hi everybody,

I have a problem on my installation which I will detail to you immediately:
Use: automatic watering + outdoor tap
The water is pumped into a large well, a submerged pump.
The well should be about 50m away from the booster (100L bladder tank).

When automatic watering starts, the pressure drops quickly. The balloon pressure switch activates the pump but despite everything the pressure eventually drops to 0 and the water flows but without pressure.

I found a trick to make watering work anyway:
I drop the pressure by drawing water, the low pressure switch switches on and starts the pump. Before reaching the high pressure which cuts the pump, I start the automatic watering: there it holds, I have the pressure which remains high and the watering can work for hours.
On the other hand, if the sprinkling works and that I manage for example by drawing a little less water to engage the HP pressure switch, the pump cannot manage to resume when BP is triggered and the pressure ends up going down slowly towards 2 bars then very quickly towards 0.
PS: I don't know the whole installation, I didn't do it.

You have a tip to correct this problem, especially since it seems that it worked properly before (dixit former owner).
I tested several settings on the booster but it is not there yet.

[raymon]

Your failure like a switch problem that influenza moment, trying to put some dgrippant above and see if key not works better.

[KLB]

The pressure switch reacts correctly, it is even quite precise in the settings.

I thought of something else, it looks like my water supply is too low.
My balloon is a Varem 100L, water inlet from below. So I told myself that air must have entered the bladder, and take the place of water.

I drained the balloon by switching off the pump + tap open, I inflated to 2,5Bar then lowered to 2Bar. Return to service but still the same.
I think I will disassemble the bladder to be sure that air is not trapped.

Does the reasoning seem logical?

[Forhorse]

the bladder inflation pressure must be 0.3bar above the switch-on pressure of the pressure switch (pump start-up)
For example if the pressure switch starts the pump at 2.5 bars, and stops it at 3.8 bars, the bladder must be inflated to 2.5 + 0.3 = 2.8 bars
why not 300grams, it's scientific calculations that I did not understand, I just retained this value.

To properly make the water connection of the tank must be at the top, precisely so that the air does not accumulate inside.

Otherwise, I already had the case of a bladder stuck against the filling hole of the balloon, because of this, not a single drop of water entered the balloon. It happened after a long period of inactivity of the installation. Air pressure on the bladder pressed the bladder against the inlet fitting, and rust did the rest.
Deflating the bladder, dismantling, quick cleaning, reassembly and re-inflation at the right pressure had solved the problem.