23
GB
5
■
with the mechanical pressure switch PM5
■
with the electronic pressure switch ZP Control 01 Basic
3.
3
Description booster unit HWX
The HWX are available in two different configurations
:
ATTENTION
Adjustment of the pressure- switch PM5
Always disconnect from the power before servicing and prevent it against accidental touch.
This switch is pre- adjusted to start the unit at approx. 1.8 bar and stop it approx. 3 bar.
Within this range, the pump works at its best efficiency. To change these values to increase/reduce the pressure, please proceed as follows:
- Remove the cover of the switch turning the nut of the small spring clockwise (counter-clockwise) will increase (reduce) the switching- off
pressure.
- Turning the nut of the large spring clockwise (counter-clockwise) will increase (reduce) the starting pressure.
- Close the switch, plug in and check the new values by controlling the pressure gauge.
- If the result is unsatisfactory repeat the procedure. Note that both springs are influenced mutual.
Please note that the changing of one switch point may be affected the other switch point and the switch on/- off- pressure should be
controlled in any case.
The switching-off pressure must be lower than the max. pressure.
(see technical data or type plate). Otherwise the pump will never stop and could be damaged. The max. reachable
pressure calculated as follows: max. deliver lift according to the identification plate minus real suction lift. The
switch off pressure should be min. 5 m (0.5 bar) less than the max. within reach pressure of the pump.
When the switch- on pressure was changed has the air pressure been adjusted inside the diaphragm vessel. The air pressure must be approx
0.2 to 0.3 bar less than starting- pressure of the unit.
Procedure:
Disconnect the power supply. Open the tap, that the system will be vented.
Remove the black cover at the rear of the tank and check the air pressure at the underlying valve with a pressure gauge.
If necessary reduce the air pressure or increase it by means of a foot operated pump.
After that the air pressure should be inspected once again.
