Mitsubishi Electric SUZ-KA24NAHZ Manual De Instalación página 8

4. Installing the refrigerant piping
A12, A18
D
D
A Front piping cover
B Piping cover
C Stop valve
D Service panel
E Bend radius : 100 mm, 3-15/16 inch-150 mm, 5-27/32 inch
A
B
D
C
Stop valve <Gas side>
A
Stop valve <Liquid side>
B
Service port
C
Open/Close section
D
(1)
B
A
C
G
H
I
E
Fig. 4-5
A Valve body
B Unit side
C Cap
en
D Local pipe side
E Pipe cover
F Service port
G Valve stem
B
c
7
A24-A42
C
B
A
E
Fig. 4-3
A B
C
D
D
E
F
F
G
G
Local pipe
E
Sealed, same way for gas side
F
Pipe cover
G
Do not use a wrench here.
H
Refrigerant leakage may result.
Use two wrenches here.
I
Fig. 4-4
(2)
B
F
A
G
H
I
E
D
Fig. 4-6
H Double spanner section
(Do not apply a spanner other than to this sec-
tion.Doing so would cause refrigerant leaks.)
I 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.)
* The figure to the left is an example only.
The stop valve shape, service port po-
A
sition, etc., may vary according to the
model.
* Turn section A only.
(Do not further tighten sections A and
B together.)
D
C Charge hose
D Service port
Fig. 4-7
4.3. Refrigerant piping (Fig. 4-3)
Please carefully consider the indoor unit location when piping lengths are less than
16 ft. (5 m) as there could be intermittent noises during normal operation that would
be noticeable in very quiet environments.
Remove the service panel D (3 screws) and the front piping cover A (2 screws)
and rear piping cover B (2 screws: KA24) (4 screws: KA30, KA36).
1 Perform refrigerant piping connections for the indoor/outdoor unit when the out-
door unit's stop valve is completely closed.
2 Vacuum-purge air from the indoor unit and the connection piping.
3 After connecting the refrigerant pipes, check the connected pipes and the indoor
unit for gas leaks. (Refer to 4.4 Refrigerant pipe airtight testing method)
4 Vacuumize the refrigerant lines through the service port of the liquid stop valve
and then open the stop valves completely (for both the liquid and gas stop
valves). This will completely connect the refrigerant lines of the indoor and out-
door units.
• If the stop valves are left closed and the unit is operated, the compressor and
control valves will be damaged.
• Use a leak detector or soapy water to check for gas leaks at the pipe connec-
tion sections of the outdoor unit.
• Do not use the refrigerant from the unit to purge air from the refrigerant lines.
• After the valve work is completed, tighten the valve caps to the correct torque:
20 to 25 N·m, 14 to 18 ft·lbs (200 to 250 kgf·cm).
Failure to replace and tighten the caps may result in refrigerant leakage. In
addition, do not damage the insides of the valve caps as they act as a seal to
prevent refrigerant leakage.
5 Use sealant to seal the ends of the thermal insulation around the pipe connec-
tion sections to prevent water from entering the thermal insulation.
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 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 0.01 MPa (0.1 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 (Fig. 4-5)
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.
C
(ø15.88, 5/8 inch: Approximately 11 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.
(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 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 mm, 3-35/64 inch
before or after connecting the pipes. Cut out the knockout in the pipe cover fol-
lowing 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 re-
main. (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 opening or closing the valve below freezing temperatures, refrigerant
may spurt out from the gap between the valve stem and the valve body, re-
sulting in injuries.
G), wait five minutes, and make sure the
2
G), wait five minutes, and make sure the
2
2 G) and measure the surrounding tem-
G). Make the necessary corrections.
2