EDM SYSHP MINI SPLIT 06 16

Table Of Contents
73
3.9 Gasghtness Test
3.9.1 Purpose
To prevent faults caused by refrigerant leakage, a gasghtness test should be performed before system commissioning.
3.9.2 Procedure
Notes for installers
Warning
Only dry nitrogen should be used for gasghtness tesng. Oxygen, air, ammable gases and toxic gases must not be used for
gasghtness tesng. Use of such gases may result in re or explosion.
Procedure
The gasghtness test procedure is as follows:
Step 1
Once the piping system is complete and the hydronic box and outdoor unit have been connected, vacuum the piping to
-0.1MPa.
Step 2
Charge the piping with nitrogen at 0.3MPa and leave for at least 3 minutes to check large leakage, then 1.5MPa leave for at
least 3 minutes to check small leakage, nally 4.3MPa leave for at least 24 hours to check micro leakage.
Aer the test period of at least 24 hours, observe the pressure in the piping and assess whether or not the observed
pressure indicates the presence of a leak. Allow for any change in ambient temperature over the test period by adjusng the
reference pressure by 0.01MPa per 1°C of temperature dierence. Adjusted reference pressure = Pressure at pressurizaon
+ (temperature at observaon temperature at pressurizaon) x 0.01MPa. Compare the observed pressure with the
adjusted reference pressure. If they are the same, the piping has passed the gasghtness test.
If the observed pressure is lower than the adjusted reference pressure, the piping has failed the test. Refer to Part 3, 3.9.3
“Leak detecon”. Once the leak has been found and xed, the gasghtness test should be repeated.
Step 3
If not connuing straight to vacuum drying (see Part 3, 3.10 Vacuum Drying”) once the gasghtness test is complete,
reduce the system pressure to 0.5-0.8MPa and leave the system pressurized unl ready to carry out the vacuum drying
procedure.
Figure 3-3.10: Gasghtness test
Outdoor unit
Hydronic box
Nitrogen
Gas pipe
Liquid pipe