Air Tight Test And Vacuum Drying - Daikin ALTHERMA HT Service Manual

Test Operation
1.2

Air Tight Test and Vacuum Drying

 Air tight test: Make sure to use nitrogen gas.
 Do this before powering the unit. (If the power has been turned on before the
 Setup:
 Pressurize the liquid and gas pipes to 4.0 MPa (40 bar) (do not pressurize more than 4.0
 Vacuum drying: Use a vacuum pump which can evacuate to –100.7 kPa (5 Torr, –755 mm
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vacuuming has been done, first setting 2-21 must be used. See "Setting of Vacuuming
Mode" on page 116.)
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3
2
Pressure reducing valve
1
Nitrogen
2
Siphon system
3
Vacuum pomp
4
Valve A
5
Gas line stop valve
6
Liquid line stop valve
7
Stop valve service port
8
Charge hose
9
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.
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.
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
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ESIE09-08B
R-410A
Test Operation