SYSTEMP – Installation Operation Manual (IOM SYSTEMP rev.N)

Table Of Contents
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9.6 COOLING CIRCUIT VACUUM DRYING OPERATIONS
WARNING!
Remote condenser air conditioners are shipped pressurised with nitrogen.
Air-cooled condensers are shipped pressurised with nitrogen.
WARNING!
Air conditioners with internal water-cooled condensers are supplied FULLY CHARGED with
refrigerant.
After all connections and seal test operations, included in the previous chapters, have been completed for the cooling cir-
cuit, it is necessary the vacuum drying operation of the cooling circuit.
The vacuum drying operation of the cooling circuit is necessary to remove any residue of the technical gasses used for sol-
dering and seal tests, atmospheric air and the water vapour that is part of it. By creating a vacuum inside the cooling line by means of
a vacuum pump, the boiling point of water (100 °C at atmospheric pressure) is lowered to the point that, once it reaches a value lower
than the temperature of the environment, humidity in the pipes turns into vapour and can, therefore, be ejected. Vacuum pumps
are necessary to perform this operation suited to the cooling circuits (ow rate of 50 litres/minute).
The procedure for carrying out vacuum in the circuit is the following:
1) Connect the pressure gauges to the cooling circuit as shown in the next picture.
2) Connect the vacuum pump and refrigerant tank to the pressure gauges.
3) Power the machine (but not the compressors) to heat the possible crankcase oil heater.
4) Verify that all circuit cocks are open.
5) Bring the pressure gauges in position for operation in vacuum phase (carry out the vacuum simultaneously from both the
liquid side and the gas side).
6) Start the vacuum pump.
7) The correct vacuum that can be achieved at the installation site is approximately - 1 BarG (1 mBarA).
8) Leave the pump running for a few hours (min. 2 hours):
If, within two hours, the pump is unable to reach approximately - 1 BarG (1 mBarA), this means that there are still traces of
humidity or there is a leak.
If a vacuum of approximately - 1 BarG (1 mBarA) is reached, maintain it for at least one hour. The test is considered a success
if, in such a period of time, there is no increase in pressure. If otherwise, it means that there is still humidity inside the pipes,
or there is a leak.
9) Should there be a leak, proceed with repairing it and repeat the previous operation, otherwise:
10) Close the pressure gauges and switch o the pump.
11) Disconnect the pump and move on to refrigerant charging operations.
A Compressor
B Pressure gauges
C Refrigerant
D Vacuum pump
A
C
D
B