11
6. Refrigerant piping work
6.4. Purging procedures leak test
PURGING PROCEDURES
Connect the refrigerant pipes (both the liquid and gas pipes) between the indoor
and the outdoor units.
Remove the service port cap of the stop valve on the side of the outdoor unit gas pipe.
(The stop valve will not work in its initial state fresh out of the factory (totally closed
with cap on).)
Connect the gage manifold valve and the vacuum pump to the service port of the
stop valve on the gas pipe side of the outdoor unit.
Run the vacuum pump. (Vacuumize for more than 15 minutes.)
Check the vacuum with the gage manifold valve, then close the gage manifold valve,
and stop the vacuum pump.
Leave it as is for one or two minutes. Make sure the pointer of the gage manifold
valve remains in the same position. Confirm that the pressure gage show -0.101MPa
(-760 mmHg).
Pipe length :
7 m [23 ft] maximum
No gas charge is needed.
Pipe length exceeding 7 m [23 ft]
Charge the prescribed
amount of gas.
Remove the gage manifold valve quickly from the service port of the stop valve.
After refrigerant pipes are connected and evacuated, fully open all stop valves on
gas and liquid pipe sides.
Operating without fully opening lowers the performance and causes trouble.
Tighten the cap to the service port to obtain the initial status.
Retighten the cap
Leak test
6.5. Drain piping work
• Ensure that the drain piping is downward (pitch of more than 1/100) to the outdoor
(discharge) side. Do not add a trap.
• Ensure that any cross drain piping is less than 20 m [65 ft] (excluding the differ-
ence of elevation). If the drain piping is long, add metal braces to prevent it from
shaking. Never provide an air vent pipe, otherwise drain may be ejected.
• Use a hard vinyl chloride pipe O.D. ø32 mm [1-1/4 in] for drain piping.
• Ensure that collected pipes are 10 cm [3-15/16 in] lower than the unit body’s drain
port.
• Do not provide any odor trap at the drain discharge port.
• Place the end of the drain piping in a position where odor is not generated.
• Do not put the end of the drain piping in any drain where ionic gases are generated.
[Fig. 6-10] (P.4)
Correct piping
Wrong piping
A
Insulation (9 mm [3/8 in] or more)
B
Downward slope (1/100 or more)
C
Support metal
K
Air bleeder
L
Raised
M
Odor trap
Grouped piping
D
O. D. ø32 mm [1-1/4 in] PVC TUBE
E
Make it as large as possible. About 10 cm [3-15/16 in].
F
Indoor unit
G
Make the piping size large for grouped piping.
H
Downward slope (1/100 or more)
I
O. D. ø38 mm [1-1/2 in] PVC TUBE for grouped piping.
(9 mm [3/8 in] or more insulation)
J
Up to 550 mm [21-21/32 in]
N
Drain hose (accessory)
O
Horizontal or slightly upward
Refrigerant pipe insulation
• After connecting refrigerant piping, insulate the joints (flared joints) with thermal
insulation tubing as shown below.
[Fig. 6-9] (P.3)
A
Pipe cover (120 mm [3/4 in] small diameter) (accessory)
B
Caution:
Pull out the thermal insulation on the refrigerant piping at the site, insert the flare nut to flare
the end, and reinsert the insulation.
Take care to ensure that condensation does not form on exposed copper piping.
C
Liquid end of refrigerant piping
D
Gas end of refrigerant piping
E
Site refrigerant piping
F
Main body
G
Pipe cover (120 mm [3/4 in] large diameter) (accessory)
H
Thermal insulation (field supplied)
I
Pull
J
Flare nut
K
Return to original position
L
Ensure that there is no gap here
M
Plate on main body
N
Tie band (accessory)
O
Ensure that there is no gap here. Point joint upwards.
1.Remove and discard the rubber bung which is inserted in the end of the unit piping.
2.Flare the end of the refrigerant piping.
3.Remove the thermal insulation on the site refrigerant piping and replace the insula-
tion in its original position.
Cautions On Refrigerant Piping
s
s
s
s
s
Be sure to use non-oxidized brazing for brazing to ensure that foreign mat-
ter or moisture do not enter into the pipe.
s
s
s
s
s
Be sure to apply refrigerating machine oil over the flare connection seating
surface and tighten the connection using a double spanner.
s
s
s
s
s
Provide a metal brace to support the refrigerant pipe so that no load is
imparted to the indoor unit end pipe. This metal brace should be provided
50 cm [19-11/16 in] away from the indoor unit’s flare connection.
*Close
*Open
Hexagonal wrench
Stop valve
*4 to 5 turns
Stop valve
(or the vacuum
pump with the
function to prevent
the back flow)
Gauge manifold
valve (for R410A)
Pressure gauge
(for R410A)
Compound pressure gauge
(for R410A)
-0.101MPa
(-760 mmHg)
Handle
Low
Handle High
Window
Charge hose
(for R410A)
Vacuum
pump
Adapter for
preventing the
back flow
Charge hose (for
R410A)
Service
port
Stop
valve
