9 Piping work and
refrigerant charge
TCGB0070 rev.3 - 04/2012
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9
Pressure lost calculation
The indoor unit is factory supplied with two Shutdown Valves which are provided with a Pressure Port . The object of these
Pressure Ports, is to offer the installer a quick connection to read the Lost Pressure in the circuit when commissioning.
Plug in a differential Manometer to the Pressure Ports and open the inlet / outlet ports
(1*)
.
The Pressure Lost is calculated from the pressure difference between the value of the inlet and the outlet water pressure.
N O T E
(1*)
If there is no having a Differential Manometer, it is possible to do this operation with just one std. Manometer
(it is advisable to use the same Manometer in order to avoid reading mistakes from different devices because of
different tolerances or adjustment).
Check the pump performance curves
Refer to the Pump Performance Curves to calculate the circuit’s Water Flow depending on the actual Pressure Drop and
the Heating Circuit type (Heating Floor, Radiators, Fan Coils).
Selection of the pump speed
The indoor unit pump should be adjusted according to Pressure Lost of the circuits and the calculated Water Flow. The
pump speed selector switch is located on the pump’s Terminal Box.
Pump speed selector
View from A
Speed indications:
Speed 1 (Low)
Speed 2 (Medium)
Speed 3 (High)
N O T E
The Pumps are factory supplied on speed 3 (High)
Water flow adjustment
The Water Flow should be adjusted by closing one of the main Shutdown Valves until the pressure matches the Pump
Performance Curves.
Finally, the differential Manometer should be removed once the Pressure Port Valves are closed.
