Pressure Kit for Solar DC Pumps with Tank
These pressure switch kits are designed for automatic pump control on solar pump installations where the holding tank is too far from your pump, and becomes impractical to run a signal cable as is required to use a standard water level switch.
The pressure switch gives a signal to our solar pump controllers’ tank sensor terminals to shut down the pump when your tank is full, and re-start pumping once the tank level has dropped.
- 19L Pressure Tank (Max Pressure: 1000kPa -Connection Size: 25mm)
- 5-way Brass Tee (1x 1″ male + 2x 1″ female + 1x male 1/4″ BSP + 1x female 1/4″ BSP)
- Pressure Gauge with male 1/4″ BSP thread
- Adjustable Pressure Switch 10 -140 PSI with female 1/4″ BSP thread
- Does not arc when opening or closing – as there is only a signal contact to the controller – no large current as with normal AC pump pressure switches.
|Dimensions||26 × 26 × 40 cm|
Quick install guides
Please remember that you need a non-return valve (sometimes called a check valve) between the pressure switch and the pump. You also need a valve at the outlet – usually a ball valve to close off the pipe at the tank inlet – so the pressure switch will work.
PRESSURE TANK PRE-CHARGE:
For PRESSURE SWITCH CONTROLLED PUMPS using a pressure tank, with a pressure differential (difference in pressure between cut-out and cut-in) of up to 140kPa (20psi), set tank air pre-charge to 20kPa (3psi) below the pump cut in pressure.
Once the pre-charge is set, no regular air charge checks are required.
Tank Pre-charge Instructions
1. Turn the power and water supply off, then open a tap to drain any pressure build up in the tank before adjusting the pre-charge pressure.
2. Use an air compressor to increase the air pressure in the tank – the air valve is exposed by unscrewing the plastic cap on top of the tank.
For example, lets say you have 20 metres elevation from the pressure switch up to the tank – this equals 29 PSI at the pressure switch (with the pipe full of water and the pump switched off). In this case, the pump will need to cut-in at a 29 PSI or greater (if the cut-in were set any lower than 29 PSI, the pump would never start as the pipe from the pressure switch to the tank being full of water makes this 29 PSI pressure). If the pressure cut-in was set to 30 PSI, we would set the pressure tank to 27 PSI.
Using our standard pressure switch as pictured below, the cut-in pressure is fixed at roughly 7 PSI below the set cut-out pressure.
General pressure switch setting instructions for included standard pressure switch:
- Connect the pressure switch terminals to the tank sensor terminals inside the solar pump controller.
- Rotate the adjusting allen key in the pressure switch clockwise all the way in to increase cut-out pressure .
- Run the pump in good sunlight with water flowing into the tank at the maximum pump flow rate & take note of the pressure gauge reading while pumping at full rate. This is the running pressure.
- Rotate the adjusting allen key on the pressure switch counter-clockwise until you notice the red ‘Tank Full’ light come on the controller – the cut-out pressure is now equal to the running pressure in the pipe.
- Now rotate the adjusting allen key clockwise again for approx. half a turn to increase the cut-out pressure slightly above the running pressure.
- Close valve at tank and observe pressure switch reading when the pump cuts out to ensure correct operation.
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