2 | INSTALLATION
16
Do not use oxygen or acetylene or other flammable or poisonous
gases in the refrigerating circuit, as they can cause explosions.
- reach a pressure equal to 0.3 Mpa
- wait 3 minutes.
- check that the pressure has not dropped
- reach a pressure equal to 1.5 Mpa
- wait 3 minutes.
- check that the pressure has not dropped
- reach a pressure equal to 3 Mpa
- adjust the reached pressure and room temperature
- leave the circuit pressurised for 1 day
- check that the pressure has not dropped
If the temperature has changed with respect to the noted value
consider that the pressure varied by 0.01 Mpa for 1 °C.
If pressure has dropped, detect the leak, fix it and repeat the test.
To detect the leak, use a solution of water and soap and check all
the joints and welds, if any.
Having verified the absence of leakages:
- create a pneumatic vacuum inside the circuit
Pneumatic vacuum
To create vacuum in the circuit:
- keep the outdoor unit shut-off valves closed
A
High pressure
B
Low pressure
1
Pressure gauge unit
2
Vacuum pump
3
3-way valve service connection
- connect the vacuum pump to the pressure gauge unit
- connect the pressure gauge unit to the service connection on the
3-way shut-off valve
- completely close the pressure reducing valve of the pressure
gauge
- fully open the low pressure valve of the pressure gauge unit
- let the vacuum pump work for at least 15 minutes
- reach a pressure that is close to -0.1 Mpa
- close the low pressure valve of the pressure gauge unit
- switch off the vacuum pump
- wait 5 minutes
- check that the pressure has not risen again
If the pressure has risen again:
1
2-way shut-off valve
2
On-off valve cover plug
3
Hex wrench
A
Opening by 1/4 of a turn
- open the 2-way shut-off valve by a quarter of a turn
- close it after 6 seconds so as to allow a small quantity of
refrigerant into the circuit
- detect the leak using a solution of water and soap
- fix the leak
- recreate the pneumatic vacuum
Take the necessary safety precautions for the system refrigerant.
It is forbidden to carry out welding operations with refrigerant inside
the cooling circuit. If necessary, the refrigerant must be recovered
and the circuit must be cleaned with nitrogen without oxygen.
It is forbidden to use detergents containing chlorine because it could
react with the refrigerant and corrode the copper pipes.
If the pressure has not risen again:
A
Opening
B
Closing
1
Service connection blanking plug
2
On-off valve shaft
3
Refrigerating pipe attachment
4
On-off valve cover plug
5
Hex wrench
- remove the tube of the pressure gauge unit from the service
connection on the 3-way shut-off valve
- fully open the unit shut-off valves
- refit the valve covering plug
Carefully check for absence of leakages from the closing point of the
plug.
Do not force beyond the stop point to prevent damaging the shaft
and causing leakage as a consequence.
