Air Leakage Test, Vacuum And Refrigerant Charge; Air Leakage Test; Vacuum; Refrigerant Charge - McQuay MDS 30 Installation Manual

8.0 Air Leakage Test, Vacuum and Refrigerant Charge

8.1 Air leakage test


To conduct air leakage test, ensure the ball valve is off.

Refer to the procedure below to avoid polluting the lubricating
oil during the leakage test.
Air leakage testing procedure
Charging Nitrogen gas
 Nitrogen gas (For R410A units: 4.15MPa, R22 units: 2.94MPa),
wait for 24 hours. If the pressure is not drop, the units pass the
air tightness testing; if pressure decrease, use soap water to
detect the leakage point.
 After charging the nitrogen gas, use soap water on the part of
brazing, flange and connection position to see if there is any
bubble occurred.
 After air leakage testing, wipe off the bubbling agent.

8.2 Vacuum


Ensure the ball valve is off before conducting vacuum.

Vacuum pressure is 650Pa and the time of vacuum is
24 hours.

Do not use refrigerant to vacuum.
8.3 Charging the refrigerant

Charge in additional refrigerant based on the piping length connection.

Additional charge required can be obtained from selection report or calculated manually with the steps as
shown below.
Additional charge amount:
= ∑ Li* Gi
= (Piping Length for 15.88mm X Additional Charge Amount)
+ (Piping Length for 12.7mm X Additional Charge Amount)
+ (Piping Length for 9.52mm X Additional Charge Amount)
+ (Piping Length for 6.35mm X Additional Charge Amount)
Caution that the additional charge amount of different pipe diameter varies base on type of refrigerant.
Pipe Diamater (mm)
R22 Additional Charge (g/m)
Pipe Diamater (mm)
R41A additional Charge (g/m)

Before charging, open the all ball valve.
Installation Manual IM-MDS_(i)
6.35 9.52 12.70
50 80 120
6.35 9.52 12.70
45 70 120
LEAKAGE TEST SKETCH
nitrogen
Do not use oxygen and other flammable
air to increase the pressure to avoid
explosion
VACUUM SKETCH
to indoor unit
to indoor unit
LO
vacuum
pump
check valve
15.88 19.05
180 290
15.88 19.05
180 260
service port
ball valve
to indoor unit
liquid pipe
gas pipe
to indoor unit
ball valve
outdoor
HI
LO
unit
pressure gauge
Remark
service port
ball valve
liquid pipe
gas pipe
ball valve
outdoor
HI
unit
compound
pressure gauge
25