Mitsubishi Electric PUMY-P36NKMU2 Installation Manual page 9

4. Installing the refrigerant piping
D
A Front piping cover
B Piping cover
C Stop valve
D Service panel
E
A
C
D
E
F
G
A
B
C Service port
D Open/Close section
E Local pipe
Fig. 4-6
1
B
(1)
D
A
E
F
C
H
(2)
Fig. 4-8
A Valve F Completely closed
B G Completely open
C Service port H Refrigerant piping side (On-site installation)
D I
E Cap J Wrench hole
C
B
A E
B
H
C
I
F Sealed, same way for gas side
G Pipe cover
H Do not use a wrench here.
Refrigerant leakage may result.
I
2
G
C
Remove the service panel D (three screws) and the front piping cover A (two
screws) and rear piping cover B (two screws).
1 Perform refrigerant piping connections for the indoor/outdoor unit when the
outdoor unit's stop valve is completely closed.
2 Vacuum-purge air from the indoor unit and the connection piping.
Evacuation
Evacuate with the valve of the outdoor unit closed and evacuate both the connec-
tion piping and the indoor unit from the service port provided on the valve of the
outdoor unit using a vacuum pump. (Always evacuate from the service port of both
liquid pipe and gas pipe.) After the vacuum reaches 650 Pa [abs] [0.0943 psi/5
Torr], continue evacuation for at least one hour or more. Then, stop the vacuum
pump and leave it for 1 hour. Ensure the degree of vacuum has not increased. (If
Finally, seal in with the liquid refrigerant through
the liquid pipe, and adjust the gas piping to obtain an appropriate amount of the
refrigerant during operation.
3 After connecting the refrigerant pipes, check the connected pipes and the
indoor unit for gas leaks. (Refer to 4.5. Refrigerant pipe airtight testing method)
4 Vacuumize the refrigerant lines through the service port of the liquid and gas
stop valves. 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 outdoor units.
and control valves will be damaged.
nection sections of the outdoor unit.
lines.
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
tion sections to prevent water from entering the thermal insulation.
Refrigerant pipes are protectively wrapped
or after connecting the pipes. Cut out the knockout in the pipe cover following the
groove and wrap the pipes.
Pipe inlet gap
(If the gaps are not closed, noise may be emitted or water and dust will enter the
unit and breakdown may result.)
Note:
<Triple Evacuation>
manifold gauges must not be used to measure vacuum. A micron gauge
must be used at all times.
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-
microns for a minimum of 1 hour.
(1) Connect the testing tools.
A B are closed and do not open them.
stop valve A and the gas stop valve B.
little.
1
sure does not decrease.
2
pressure does not decrease.
3 Pressurize to 4.15 MPa [601 PSIG] and measure the surrounding tempera-
ture and refrigerant pressure.
pipes have passed the test and there are no leaks.
change by about 0.01 MPa [1.5 PSIG]. Make the necessary corrections.
(4) If the pressure decreases in steps (2) or (3), there is a gas leak. Look for the
source of the gas leak.
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C of the liquid
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