Unit installation

Use and Maintenance Manual Air-cooled water chillers and Heat Pumps R-PAE/R-PAH/EAH Rev. 1 del 03/09
5.6.3 Check of the setting up
The setting up must be checked while the unit is working in conditions as close as possible to the nominal ones.
Make sure:
Ø The thermal load is adequate;
Ø The water capacity and the evaporating and condensing water temperatures are close to the nominal ones.
Check the gas charge: the charge will be complete when, after 10 minutes of operation in nominal conditions, no
bubbles are shown in the liquid sight glass.
Check the gas overheating on the compressor intake as shown below and, if necessary, set the thermostatic valve.
While the unit is working in nominal conditions, connect a manometer on the low pressure side. Check the gas
temperatature on the compressor intake (Picture 41) by means of a thermometer (Picture 40).
The overheating intake value is given by the difference between the temperature shown on the thermometer and the
saturation temperature (dew value for mixture) corresponding to the pressure shown on the manometer. If
overheating is higher than 10°C, the thermostatic valve must be opened, while if it is lower than 5°C the valve
must be shut off ( Picture 42 cap removal and Picture 43 opening adjustment).
Valve adjusting operations must be always carried out with caution, turning the adjusting screw only half turn
each time; wait for few minutes before every new adjustment in order to allow the unit to reach steady conditions.
Gas: R407C
Intake Temp. 7°C
Suction pressure:
3,9 bar = +2°C
Overheating: 5K
Picture 40 Picture 41
Picture 42 Picture 43
The thermostatic valve adjustment is a very delicate operation, therefore it must be carried out by a skilled
technician.
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