-
180
-
Airtighteness test completed
Vacuuming begins
Vacuuming completed
Vacuum gauge check
When the vacuum gauge's needle pointer creeps up, there is moisture left in the system
or a leak. Pull air again after you have checked the system for a leak and rectified it. Use
a reverse flow stop adapter to prevent the vacuum pump's lubricant oil from flowing into
the refrigerant system.
Please run the vacuum pump for at
least one hour after the vacuum gauge
shows -101kPa or lower. (-755mmHg
or lower)
No increase in the reading of the
vacuum gauge's needle pointer.
(3)
Air tightness test and air purge
●
Always use a vacuum pump to purge air trapped within an indoor and the refrigerant piping.
(a)
Air tightness test
1) When all the flare nuts on both indoor and outdoor unit sides are fastened. Conduct an air-tightness test from the service
valves charge port with the outdoor unit service valves (on both liquid and gas sides) closed tightly to check whether the
system has no leaks.
2) Use nitrogen gas in the air-tightness test. Do not use gas other than nitrogen gas under any circumstances.
Conduct the air-tightness test by applying 4.15MPa (42kg/cm
3
G) of pressure.
3) Do not apply the specified pressure at once, but increase pressure gradually.
a) Raise the pressure to 0.5 MPa, and then stop. Leave it for five minutes to see if the pressure drops.
b) Then raise the pressure to 1.5 MPa, and stop. Leave it for five more minutes to see if the pressure drops.
c) Then raise the pressure to the specified level (4.15 MPa), and record the ambient temperature and the pressure.
d) If the pressure does not drop after the units is left for approximately one day, the airtighteness is acceptable.
When the ambient temperature changes 1˚C, the pressure also changes approximately 0.01 MPa. The pressure. if
changed, should be compensated for.
(b)
Air purge
When a vacuum air purge is completed, remove the valve rod cap nuts and open the service valves (both liquid and gas sides)
as illustrated below. After you have made sure that the valves are in the full-open position, tighten the cap nuts (for the valve
rads and charge ports).
• Open the valve rod until it touches the stopper. You
need not apply lorce to push it further.
• When an operation is completed, replace the cap nut
and tighten it as before.
Open
Hexagonal Head Wrench
(M4)
Liquid/gas operation
(4)
Refrigerant quantity
(a)
This unit is shipped from the factory with the refrigerant sufficient for an installation involving 30m of
piping, and does not necessitate additional refrigerant charge as long as the pipe length is 30m or less.
(b) When the pipe length exceeds 30m but remains within 50m, add refrigerant according to the table below
(showing an additional quantity required for each meter of the pipe exceeding 30m) by metering for the
quantity determined by the actual pipe length.
(Example) When 302 model unit is used in a new installation involving 45m piping
Additional charge quantity:0.9kg = (45-30)m
0.06kg/m
Mark
302
Quantity charged for shipment (for 30m of piping)(kg)
2.95
Additional charge quantity per meter (kg/m)
0.06
Model
Compound pressure gauge Pressure gauge
Gauge manifold
Handle Hi
Gas service valve
Handle Lo
Liquid service valve
Charge port
-101kPa
(-755mmHg)
Charge hose
Charge hose
Vacuum
pump
Check valve
Vacuum adapter
