Mitsubishi Electric PUZ-A·NHA Installation Manual page 6

4. Installing the refrigerant piping
A
B
D
C
A Stop valve <Liquid side>
B Stop valve <Gas side>
C Service port
D Open/Close section
Fig. 4-4
(1)
B
A
C
I
J
F
E
Type A
Fig. 4-5
B
(2)
A
I
F
Fig. 4-6
4.6. Addition of refrigerant
• Additional charging is not necessary if the pipe length does not exceed 20 m, 70 ft
for A12-A36, 30 m 100 ft for A42.
• If the pipe length exceeds the specified length above, charge the unit with addi-
tional R410A refrigerant according to the permitted pipe lengths in the chart below.
* When the unit is stopped, charge the unit with the additional refrigerant through
the liquid stop valve after the pipe extensions and indoor unit have been
vacuumized.
When the unit is operating, add refrigerant to the gas check valve using a
safety charger. Do not add liquid refrigerant directly to the check valve.
Max pipe
Model
length
A12, A18 30 m, 100 ft
A24, A30, A36 50 m, 165 ft
A42 50 m, 165 ft
6
B
A
C
H
D
E
F
I
G
E Local pipe
F Sealed, same way for gas side
G Pipe cover
H Do not use a wrench here.
Refrigerant leakage may result.
I Use two wrenches here.
B
A
D
D
K
I
J
F
E
Type B
G
D
H
J
E
Max height
20 m 25 m
difference
70 ft 80 ft
0.06 kg
30 m, 100 ft 0
2 oz
0.17 kg
30 m, 100 ft 0
6 oz
30 m, 100 ft 0 0
4.4. Refrigerant pipe airtight testing method
(1) Connect the testing tools.
• Make sure the stop valves A B are closed and do not open them.
• Add pressure to the refrigerant lines through the service port C of the liquid
stop valve D.
(2) Do not add pressure to the specified pressure all at once; add pressure little by little.
1 Pressurize to 0.5 MPa (5 kgf/cm
pressure does not decrease.
2 Pressurize to 1.5 MPa (15 kgf/cm
pressure does not decrease.
3 Pressurize to 4.15 MPa (41.5 kgf/cm
perature and refrigerant pressure.
(3) If the specified pressure holds for about one day and does not decrease, the pipes
have passed the test and there are no leaks.
• If the surrounding temperature changes by 1 °C, the pressure will change by
about 0.03 MPa (0.3 kgf/cm
(4) If the pressure decreases in steps (2) or (3), there is a gas leak. Look for the
source of the gas leak.
4.5. Stop valve opening method
(1) Gas side of A24-A42 (Fig. 4-5)
Type A
1 Remove the cap, then turn one-quarter rotation counter-clockwise with a flat-bladed
screwdriver to complete open.
2 Check that the valves are fully open, then return the cap to its original state and
tighten it down.
Type B
1 Remove the cap, pull the handle toward you and rotate 1/4 turn in a counterclock-
wise direction to open.
2 Make sure that the stop valve is open completely, push in the handle and rotate
the cap back to its original position.
(2) Liquid side of A24-A42 and Gas/Liquid side of A12, A18 (Fig. 4-6)
1 Remove the cap and turn the valve rod counterclockwise as far as it will go with
the use of a 4 mm hexagonal wrench. Stop turning when it hits the stopper.
(ø6.35, 1/4 inch: Approximately 4.5 revolutions) (ø9.52, 3/8 inch: Approximately
10 revolutions)
2 Make sure that the stop valve is open completely, push in the handle and rotate
the cap back to its original position.
A Valve
B Unit side
C Operation section
D Cap
E Local pipe side
F Pipe cover
G Service port
H Wrench hole
Refrigerant pipes are protectively wrapped for A24-A42
• The pipes can be protectively wrapped up to a diameter of ø90 mm, 3-35/64 inch
before or after connecting the pipes. Cut out the knockout in the pipe cover follow-
ing the groove and wrap the pipes.
Pipe inlet gap for A24-A42
• Use putty or sealant to seal the pipe inlet around the pipes so that no gaps remain.
(If the gaps are not closed, noise may be emitted or water and dust will enter the
unit and breakdown may result.)
* After charging the unit with refrigerant, note the added refrigerant amount on
the service label (attached to the unit).
Refer to the "1.5. Using R410A refrigerant air conditioners" for more informa-
tion.
• Be careful when installing multiple units. Connecting to an incorrect indoor unit can
lead to abnormally high pressure and have a serious effect on operation perform-
ance.
Additional refrigerant charging amount (kg/oz)
27 m 30 m 33.5 m 36.6 m
90 ft 100 ft 110 ft 120 ft
0.11 kg 0.17 kg
– –
4 oz 6 oz
0.34 kg 0.51 kg 0.68 kg 0.85 kg
12 oz 18 oz 24 oz 30 oz
0.17 kg 0.34 kg
0 0
6 oz 12 oz
2
G), wait five minutes, and make sure the
2
G), wait five minutes, and make sure the
2
G) and measure the surrounding tem-
2
G). Make the necessary corrections.
I Double spanner section
(Do not apply a spanner other than to this sec-
tion. Doing so would cause coolant leaks.)
J Seal section
(Seal the end of the heat insulation material at
the pipe connection section with whatever seal
material you have on hand so that water does
not infiltrate the heat insulation material.)
K Handle
40 m 43 m 45.5 m 48.8 m
130 ft 140 ft 150 ft 160 ft
– – – –
1.02 kg 1.19 kg 1.36 kg 1.53 kg
36 oz 42 oz 48 oz 54 oz
0.51 kg 0.68 kg 0.85 kg 1.02 kg
18 oz 24 oz 30 oz 36 oz
50 m
165 ft
–
1.70 kg
60 oz
1.19 kg
42 oz