Mitsubishi Electric Mr.Slim PUHZ-SP125V Installation Manual page 7

4. Installing the refrigerant piping
A
C
D
E
F
G
A Stop valve <Liquid side>
B Stop valve <Gas side>
C Service port
D Open/Close section
Fig. 4-4
(1)
B
A
C
G
H
I
E
D
Fig. 4-5
A Valve H Double spanner section
B Unit side (Do not apply a spanner other than to this section.
C Cap Doing so would cause coolant leaks.)
D Local pipe side I Seal section
E Pipe cover (Seal the end of the heat insulation material at the
F Service port pipe connection section with whatever seal material
G Wrench hole you have on hand so that water does not infiltrate
the heat insulation material.)
B
C
Fig. 4-7
4.6. Addition of refrigerant
• Additional charging is not necessary if the pipe length does not exceed 30 m.
• If the pipe length exceeds 30m, charge the unit with additional 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 vacu-
umized.
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.
* 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.
B
D
E
F
G
E Local pipe
F Sealed, same way for gas side
G Pipe cover
(2)
B
F
A
C
G
H
I
E
D
Fig. 4-6
A
* The figure to the left is an example only.
The stop valve shape, service port posi-
tion, etc., may vary according to the model.
* Turn section A only.
(Do not further tighten sections A and B
D
together.)
C Charge hose
D Service port
4.4. Refrigerant pipe airtight testing method (Fig. 4-4)
(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 A .
(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
sure 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 0.01 MPa (0.1 kgf/cm G). Make the necessary corrections.
2
(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
The stop valve opening method varies according to the outdoor unit model. Use the
appropriate method to open the stop valves.
(1) Gas side (Fig. 4-5)
1 Remove the cap and turn the valve rod counterclockwise as far as it will go with
the use of a 5 mm hexagonal wrench. Stop turning when it hits the stopper.
(ø 15.88: Approximately 13 revolutions)
2 Make sure that the stop valve is open completely and rotate the cap back to its
original position.
(2) Liquid side (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.
(ø9.52: 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.
Refrigerant pipes are protectively wrapped
• The pipes can be protectively wrapped up to a diameter of ø90 before or after
connecting the pipes. Cut out the knockout in the pipe cover following the groove
and wrap the pipes.
Pipe inlet gap
• 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.)
Precautions when using the charge valve (Fig. 4-7)
Do not tighten the service port too much when installing it, otherwise, the valve core
could be deformed and become loose, causing a gas leak.
After positioning section B in the desired direction, turn section A only and tighten it.
Do not further tighten sections A and B together after tightening section A.
Warning:
When installing the unit, securely connect the refrigerant pipes before starting
the compressor.
• 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
performance.
Permitted
Model
pipe length
SP100 - 30 m
SP125, 140 - 40 m
G), wait five minutes, and make sure the pres-
2
G), wait five minutes, and make sure the
2
G) and measure the surrounding tem-
2
Additional refrigerant charging
Permitted
amount
vertical
difference
31 - 40 m 41 - 50 m
- 30 m –
- 30 m 0.6 kg
–
–
7