Panasonic CS-25XKE Service Manual page 37

12.3.3 Air Tightness Test on the Refrigerating System
Do not purge the air with refrigerants but use a vacuum pump to vacuum the installation.
There is no extra refrigerant in the outdoor unit for air purging.

Before system is charged with refrigerant and before the refrigerating system is put into operation, below site test
procedure and acceptance criteria shall be vertified by the certified technicians, and/or the installer.

Be sure to check whole system for gas leakage.
1)
Preparation
2)
(Step 1-2)
3)
Evacuation
4)
(Step 3-4)
5)
Tightness Test
6)
with Inert Gas
(Step 5-7) 7)
8)
Leak detection
Pressure YES
drop? and repair
(Step 8)
(Step 9-12)
NO
Recovery of
13) If no leak,
Test Gas
(Step 13)
14) Disconnect the charging hose from the service port of the
Evacuation
15) Tighten the service port caps of the 3-way valve at a torque
(Step 3-4)
16) Remove the valve caps of both of the 2-way valve and
Open 2 and 3 17) Open both of the valves, using a hexagonal wrench (4 mm).
valves
(Step 14-18)
18) Mount back the valve caps onto the 2-way valve and the
Complete
Notes:
Recommended use of any of the following leak detector,
I) Universal Sniffer leak detector
II) Electronic halogen leak detector
III) Ultrasonic Leak Detector
AIR PURGING METHOD IS PROHIBITED FOR R32 SYSTEM
Connect a charging hose with a push pin to the Low side of a charging set and the service port of the 3-way valve.
Attach the gauge manifold set correctly and tightly. Make sure that both valves of the manifold gauge (low pressure and
high pressure) is in close position.
Connect the center hose of the manifold gauge to a vacuum pump.
Turn on the power switch of the vacuum pump, then turn open the low side manifold gauge valve and make sure that the
needle in the gauge moves from 0 cmHg (0 MPa) to –76 cmHg (–0.1 MPa) or vacuum until 500 microns is achieved. This
process continues for approximately ten minutes. Then close the low side manifold gauge valve.
Remove the vacuum pump from the centre hose and connect the center hose to cylinder of any applicable inert gas as
test gas.
Charge test gas into the system and wait until the pressure within the system to reach min. 1.04 MPa (10.4 barg).
Wait and monitor the pressure reading on the gauges. Check if there is any pressure drop. Waiting time depends on the
size of the system.
If there is any pressure drop, perform step 9-12. If there is no pressure drop, perform step 13.
9) Use Gas Leak Detector to check for leaks. Must use the detection equipment with a
sensitivity of 5 grams per year of test gas or better.
10) Move the probe along the air conditioning system to check for leaks, and mark for repair.
11) Any leak detected and marked shall be repaired.
12) After repair, repeat evacuation steps 3-4 and
tightness test steps 5-7.
Check the pressure drop as in step 8.
Recover the test gas. Perform evacuation of steps 3-4.
Then proceed to step 14.
3-way valve.
of 18 N•m with a torque wrench.
3-way valve.
It is recommended to allow refrigerant slowly fl ow into the refrigerant
system to prevent refrigerant freezing. Slightly open 2-way valve for
5 seconds then close the valve. Repeat this action for 3 cycles then
fully open the valve.
3-way valve to complete this process.
Indoor unit
Tank
Cylinder
Inert
Vacuum
gas
pump
37
Liquid side
Two-way valve
Close
Gas side
Three-way valve
OPEN
CLOSE
Outdoor unit
Close