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___________________________________RAH / PAH Ka_________________________________
Periodically verify that the mechanical lter is clean, to prevent a decrease of the ow rate of the uid to cool due to excessive pressure drops.
During unit operation, the hydraulic system pressure must always be between 1.5 and 3.5 bar.
• The hydraulic system has been correctly lled and air totally eliminated.
• Hydraulic connections are correctly done and are leak-free;
• the uid to be cooled circulates freely and in the right direction, in the evaporator;
• the ow rate of the circulating uid to cool is the same of the designed one;
• the valves on the compressor and along the cooling line are in the status (open or closed) suitable to a right unit operation;
• if required, the hydraulic line contains the needed antifreeze mixture in the required concentration;
• the value of regulation temperature and of the anti-freeze alarm, on the microprocessor, are correctly set;
• The designed water ow to the evaporator is granted;
• The hydraulic circuit valves are open;
• All safety requirements have been respected;
• The spaces to be left free have been respected;
• Electrical connections have been correctly done;
• The voltage is within a tolerance of +/- 10% in comparison to the unit nominal one;
• The tightening of all electrical and hydraulic connections has been well done.
4.3 START-UP
The start-up of the unit must be carried out by a skilled refrigeration technician authorized by the Manufacturer.
4.3.1 SWITCHING ON
Before the unit start-up or before a long break, check that the parameter set on the microprocessor are coherent to the required operating conditions.
To switch the device on, turn the main switch to ON position, to give power supply to the unit.
Then, press the ON/OFF button on the microprocessor keyboard, and switch it to ON.
If the ON/OFF remote contact is closed, the circulation pump, if present, controlled by the microprocessor, shall be immediately switched on.
After a delay time, settable by microprocessor, the fans shall start and, then all the compressors one after the other, according to the cooling capacity required to
meet the request.
Once the machine has reached a steady operation, the technician carrying on the rst startup must verify the unit functioning parameters and that:
a) the safety high pressure switches work, are correctly installed and calibrated;
b) the calibration pressure is indicated on the external safety valves and their value is the required one;
c) there are no refrigerant leakages.
The collected data must be recorded on the First Commissioning module attached to the Handbook.
A copy of the First Commissioning Report, dutifully lled out, must be transmitted to the Manufacturer, in order to make the device warranty
effective.
During rst commissioning operations, the technician must check that safety (high- and low-pressure switches, water differential pressure switch, anti-
freeze thermostat, etc.) and management devices (regulation thermostat, condensation pressure adjustment device, etc.) properly work.
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