How to set the pressure during commissioning with the OEG control group or Thermador?

As a reminder, (as summarized in this article) whatever your hardware, the steps to commission a pressurized system with Dualsun SPRING panels are as follows:

• Filling with water

• Glycol filling

• Pressure adjustment

• Flow adjustment

• Setting the back-up

Whether for the OEG group or the Thermador group, the steps are the same, products are slightly different but the principle is the same:

To fill and degas the solar system, you can use a solar filling station with a volume flow of 12 l/min and a delivery height of 50m (e.g. rinsing and filling station SBS 2000).

To commission the installation, follow these steps:

• During the entire commissioning, do not supply the solar station

• Make a first filling with water, in order to identify any leaks

• Fill the glycol water tank, ensuring that it is clean.

• Connect the transparent hose to the degasser and put it inside the tank of the filling station.

• Connect the flexible pipes from the filling station to the level of the filling (7) and emptying (8) valves on the hydraulic unit as indicated above
  
  

• Close the valve on the flow meter so that the cavity on the ball valve flow meter is in a horizontal position (see illustration).

• Start the filling station.

• Open the drain valve.

• Gradually open the filling valve, taking care not to exceed the maximum admissible pressure of 2 bars in the panels (pressure at the level of the pressure gauge of the solar station such that: p < pmax=2+H/10, where H is the height between the solar station and the top of the panels).

• Check the glycol level in the filling station reservoir. Add fluid, if needed. The solar liquid must circulate for at least 30 minutes before the transparent flexible tube at the back of the filling station no longer indicates air bubbles in the solar liquid.

• During this time, check the tightness of the system.

• Turn the valve of the flowmeter for one minute to pass part of the fluid through the circulator (Wilo pump).

• Return the flow meter valve to horizontal

• After checking that the solar liquid returns clearly to the tank, carry out “water hammering”. For that :

  • Close the degasser

  • Lower the pressure between 1 and 1.5 bar by slightly closing the filling valve

  • Completely close the return valve.

  • The pressure increases on the pressure gauge, once it reaches the maximum allowable pressure (pmax=2+H/10), fully open the drain valve.

  • Raise the pressure to approximately 2 bars.

  • Open the degasser.

  • Observe the gassing of air at the transparent tube.

  • Repeat this procedure until the pressure quickly reaches the maximum pressure pmax after closing the return valve and there are no more air bubbles escaping from the degasser.

• Determine the operating pressure p to be adjusted: p = 1.5 + H/10.

• For simplicity, move the pressure indicator to this pressure.

• Close the degasser permanently

• Lower the pressure between 1 and 1.5 bar by slightly closing the filling valve

• Completely close the drain valve

• The pressure increases: close the filling valve once the pressure gauge reaches the pressure p to be adjusted.

  • If the valve was closed too soon and the pressure is too low: reopen the filling valve slightly then close it.

  • If the valve was closed too late and the pressure is too high: reopen the drain valve, then the filling valve and repeat the operation.

• Once the correct pressure is set, stop the filling station

• Check that both flow meter valves are closed.

For filling and degassing the solar system, you can, for example, use a solar filling station with a volume flow of 12 l/min and a delivery height of 50 m.

• Make sure that the solar liquid is filled only in a clean tank.

• Vent the flexible hose from the station.

• Connect the flexible hose as shown below with the pump group.

• Close the valve on the flow meter so that the cavity on the ball valve flow meter is in the horizontal position (see illustration).

• Start the pump and open the shut-off valve in the flow and return. Check the glycol level in the filling station reservoir. Add fluid, if needed. The solar liquid must circulate for at least 30 minutes before the transparent flexible tube at the back of the filling station no longer indicates air bubbles in the solar liquid.

• During this time, check the tightness of the system.

• After checking that the solar liquid returns clearly to the tank, you should continue with the so-called "water hammer". The return valve must be closed when the pump on the filling station is running. The pressure gauge on the pump set indicates an increase in pressure. This gradual increase in pressure demonstrates that there is no air coming out of the solar system. A rapid opening of the return valve causes a drop in pressure. Repeat this procedure until the pressure quickly reaches the maximum value of 1.5 bar + H/10 after closing the return valve.
  
  

  Translation : Direction d’écoulement = liquid flow direction Robinet à Bille ouvert = ball valve open

• Remove the flexible pipes from the solar station, put the regulating valve on the flow meter in a vertical position, close the shut-off valves on the flow meter (see illustration). The pump group is now ready for flow adjustment.The flow rate is read on the lower edge of the float.

Unlike the Dualsun solar station, it is not necessary during commissioning to close the blue valve (ball valve no. 2).

> To learn more, go to our article : How to carry out a hydraulic commissioning with Dualsun SPRING panels?