REFRIGERANT PIPING &
REFRIGERANT CHARGE
11.5. PIPING CONNECTION FOR AquaFREE
Take protection cover away from the indoor unit, and install
Refrigerant piping and Water piping down wards.
¡
Piping location
Refrigerant
Refrigerant
liquid piping
gas piping
43
276
¡
AquaFREE Refrigerant Piping size
Pipe Size
Unit
Gas Pipe
3 HP
15.88 (5/8)
4 HP
15.88 (5/8)
5 HP
15.88 (5/8)
Dimensions of the flared pipe
¡
Nominal
External
Diameters
diameters
1/4
6.35
3/8
9.53
1/2
12.70
5/8
15.88
¡
Thickness of the Copper Pipes
Nominal
External
Diameters
diameter
1/4
6.35
3/8
9.53
1/2
12.70
5/8
15.88
PMML138A_R1-eng-fre.indb 29
Refrigerant
Refrigerant
liquid piping
gas piping
43
276
(mm)
Liquid Pipe
9.53 (3/8)
9.53 (3/8)
9.53 (3/8)
(mm)
A
+0/-0.4
9.1
13.2
16.6
19.7
(mm)
R410A
0.80
0.80
0.80
1.00
¡
Dimensions of the Flare Nut
(mm)
Nominal
External
B
Diameters
diameter
1/4
6.35
17
3/8
9.53
22
1/2
12.70
26
5/8
15.88
29
¡
Flare nuts Tightening Torque
Tightening Torque
Pipe Size
(N.m)
Ø 9.53 mm
40
Ø 15.88 mm
80
11.5.1. BRAZING WORK
ATTENTION:
Use nitrogen gas for blowing during pipe brazing. If oxygen,
acetylene or fluorocarbon gas is used, it will cause an explosion or
poisonous gas.
A lot of oxidation film will occur inside of tubes if no nitrogen
gas blowing is performed during brazing work. This film will be
flecked off after operation and will circulate in the cycle, resulting
in clogged expansion valves, etc. This will cause bad influence to
the compressor.
Use a reducer valve when nitrogen gas blowing is performed
during brazing. The gas pressure should be maintained within
0.03 to 0.05 Mpa. If a excessively high pressure is applied to a
pipe, it will cause an explosion.
11.5.2. REFRIGERANT CHARGE
CAUTION:
Do not charge OXYGEN, ACETYLENE, or other flamma-
ble and poisonous gases into the refrigerant because an
explosion can occur. It is recommended that oxygen free
nitrogen be charged for these types of tests cycle when
performing a leakage test or an airtight test. These types of
gases are extremely dangerous,
Insulate the unions and flare-nuts at the piping connection
part completely.
Insulate the liquid piping completely to avoid a decrease of
performance; if not, it will cause sweating on the surface of
the pipe.
Charge refrigerant correctly. Overcharging or insufficient
charging could cause a compressor failure.
Check for refrigerant leakage in detail. If a large refrigerant
leakage occurred, it would cause difficulty with breathing or
harmful gases would occur if a fire were being used in the
room.
If the flare nut is tigthened too hard, the flare nut may crack
after a long time and cause refrigerant leakage.
PMML0138A-rev.1 - 11/2009
29
19/11/2009 14:45:33