Leak Test And Vacuum Drying - Daikin CMSQ200A7W1B Service Manual

SiBE28-805

1.2.3 Leak Test and Vacuum Drying

The units were checked for leaks by the manufacturer.
After connecting the field piping, perform the following inspections.
1.2.3.1 Preparations
Referring to figure 19, connect a nitrogen tank, a cooling tank, and a vacuum pump to the
outdoor unit and perform the airtightness test and the vacuum drying. The stop valve and valve
A in figure 19 should be open and closed as shown in the table below when performing the
airtightness test and vacuum drying.
State of the valve A and the stop valve
Performing the airtightness test and
vacuum drying
1.2.3.2 Airtightness Test and Vacuum Drying
Note:
Make sure to perform airtightness test and vacuum drying using the service ports
of the stop valves of the liquid side and of the gas side. (For the service port
location, refer to the "Caution" label attached on the front panel of the outdoor
unit.)
Note:
Make sure to use 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.
1. Evacuate the system from the liquid and gas pipes by using a vacuum pump for more than 2
Test Operation
Pressure
reducing valve
Tank
Nitrogen Measuring
instrument
See "1.2.5.3 Stop valve operation procedure" on page 70 for details on
handling the stop valve.
To prevent entry of any contamination and to prevent insufficient pressure resistance,
always use the special tools dedicated for working with R-410A refrigerant.
Airtightness test:
Vacuum drying: Use a vacuum pump which can evacuate to –100.7 kPa (5 Torr, –755 mm
Hg)
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.
Outdoor unit
Gas line stop valve Liquid line
stop valve
Valve A
Charge
Stop valve
Vacuum
hose
service port
pump
fig. 19
Valve A
Open
Test Operation
Indoor Indoor
unit unit
Dotted lines represent on site piping
To indoor unit
Liquid side Gas side
stop valve stop valve
Close Close
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