Charging With Refrigerant; Sealing Test - Fujitsu AJ**A72LBTF Installation Instruction Sheet

5. CHARGING WITH REFRIGERANT

Fig. 5-1 Connection system
A) In case of connected one out door unit
B) In case of connected many outdoor units
Fig. 5-2
Valve
Open
Cap
Close

5.1. SEALING TEST

• Do not apply shock during sealing test.
It can rupture the pipes and cause serious injury.
• Do not block the walls and the ceiling until the sealing test and the charging of the refrigerant gas have been
completed.
After connecting the pipes, perform an sealing test.
Pressurize nitrogen gas to 4.15 MPa to perform the sealing test.
Recheck that the spindle of the 3-way valve are closed before performing a sealing test. (Fig. 5-2)
Pour nitrogen gas through both the liquid pipe and the gas pipe.
* When connecting multiple units, pour nitrogen through 3 locations: liquid pipe, gas pipe, and oil pipe.
Check all flare connections and welds.
Then, check that the pressure has not decreased.
Compare the pressures after pressurizing and letting it stand for 24 hours, and check that the pressure has not decreased.
* When the outdoor temperature changes 5 °C, the test pressure changes 0.05 MPa.
If the pressure has dropped, the pipe joints may be leaking.
Find and repair the area that is leaking.
If a leakage is found, immediately repair it and perform a sealing test again.
After completing the sealing test, release the nitrogen gas from both valves.
Release the nitrogen gas slowly.
En-28
9374241033_IM_en_p18-36.p65
Outdoor unit
Pressure gauge
Indoor Indoor
unit unit
Outdoor unit
Outdoor unit
Charging cap
Spindle
Open
Hexagon
wrench
Close
CAUTION
28
Pressure regulating valve
Nitrogen
R410A
Vaccum
Scale
pump
Pressure gauge
Indoor Indoor
unit unit Vaccum
pump
Table 5-1
Pipe Spindle
Liquid
28.0 to 32.0 N·m
—
valve (280 to 320 kgf·cm)
Gas 27.0 to 30.0 N·m 60.0 to 65.0 N·m
valve
(270 to 300 kgf·cm) (600 to 650 kgf·cm)
Oil 20.0 to 25.0 N·m
—
(200 to 250 kgf·cm)
valve
26/8/2008, 18:23
Pressure regulating valve
Nitrogen
R410A
Scale
Cap Charging cap
12.5 to 16.0 N·m
(125 to 160 kgf·cm)
12.5 to 16.0 N·m
(125 to 160 kgf·cm)
12.5 to 16.0 N·m
(125 to 160 kgf·cm)