Air Tight Test And Vacuum Drying - Daikin ERSQ 011AAV1 Service Manual

Test Operation
1.2

Air Tight Test and Vacuum Drying

74
Air tight test: Make sure to use nitrogen gas.
Do this before powering the unit.
Setup:
1
3
2
1 Pressure reducing valve
2 Nitrogen
3 Siphon system
4 Vacuum pomp
5 Valve A
6 Gas line stop valve
7 Liquid line stop valve
8 Stop valve service port
9 Charge hose
The leak test must satisfy specification EN 378-2.
1. Vacuum leak test
Evacuate the system from the liquid and gas piping to –100.7 kPa (5 Torr).
Once reached, turn off the vacuum pump and check that the pressure does not rise
for at least 1 minute.
Should the pressure rise, the system may either contain moisture (see vacuum drying
below) or have leaks.
2. Pressure leak test
Break the vacuum by pressurizing with nitrogen gas to a minimum gauge pressure of
0.2 MPa (2 bar).
Never set the gauge pressure higher than the maximum operation pressure of the
unit, i.e. 4.0 MPa (40 bar).
Test for leaks by applying a bubble test solution to all piping connections.
Make sure to use a recommended bubble test solution from your wholesaler.
Do not use soap water, which may cause cracking of flare nuts (soap water may
contain salt, which absorbs moisture that will freeze when the piping gets cold), and/
or lead to corrosion of flared joints (soap water may contain ammonia which causes a
corrosive effect between the brass flare nut and the copper flare).
3. Discharge all nitrogen gas.
Pressurize the liquid and gas pipes to 4.0 MPa (40 bar) (do not pressurize more than 4.0
MPa (40 bar)). If the pressure does not drop within 24 hours, the system passes the test. If
the pressure drops, check where the nitrogen leaks from.
Vacuum drying: Use a vacuum pump which can evacuate to –100.7 kPa (5 Torr, –755 mm
Hg). Connect the vacuum pump to both service port of the gas stop valve and the liquid stop
valve to increase efficiency.
1. Evacuate the system from the liquid and gas pipes by using a vacuum pump for more
than 2 hours and bring the system to –100.7 kPa. After keeping the system under that
condition for more than 1 hour, check if the vacuum gauge rises or not. If it rises, the
system may either contain moisture inside or have leaks.
2. Following should be executed if there is a possibility of moisture remaining inside the
pipe (if piping work is carried out during the raining season or over a long period of time,
rainwater may enter the pipe during work).
7 6
5
8
4 9
ESIE09-08
R-410A
Test Operation