Ø6.35; Ø12.7; Fdt, Fden Fdu, Fdum, Srk; Ø9.52 - Mitsubishi Heavy Industries FDE40ZMXVG Technical Manual

Service valve size (mm) Tightening torque (N m)
ø6.35
ø9.52
ø12.7
ø15.88
5) Air tightness test
① Although outdoor and indoor units themselves have been tested for air tightness at the factory, check the connecting pipes after the installation work for air tightness from the
service valve's check joint equipped on the outdoor unit side. While conducting a test, keep the service valve shut all the time.
a) Raise the pressure to 0.5 MPa, and then stop. Leave it for five minutes to see if the pressure drops.
b) Then raise the pressure to 1.5 MPa, and stop. Leave it for five more minutes to see if the pressure drops.
c) Then raise the pressure to the specified level (4.15 MPa), and record the ambient temperature and the pressure.
d) If no pressure drop is observed with an installation pressurized to the specified level and left for about one day, it is acceptable. When the ambient Temperature fall 1℃ , the pressure
also fall approximately 0.01 MPa. The pressure, if changed, should be compensated for.
e) If a pressure drop is observed in checking e) and a) – d), a leak exists somewhere. Find a leak by applying bubble test liquid to welded parts and flare joints and repair it. After
repair, conduct an air-tightness test again.
② In conducting an air-tightness test, use nitrogen gas and pressurize the system with nitrogen gas from the gas side. Do not use a medium other than nitrogen gas under any circumstances.
6) Evacuation
＜ W ork flow ＞
When the system has remaining moisture
inside or a leaky point, the vacuum gauge
indicator will rise.
Check the system for a leaky point and
then draw air to create a vacuum again.
Pay attention to the following points in addition to the above for the R410A and compatible machines.
To prevent a different oil from entering, assign dedicated tools, etc. to each refrigerant type. Under no circumstances must a
○
gauge manifold and a charge hose in particular be shared with other refrigerant types (R22, R407C, etc.).
○ Use a counterflow prevention adapter to prevent vacuum pump oil from entering the refrigerant system.
7) Additional refrigerant charge
(1) Calculate a required refrigerant charge volume from the following table.
Additional charge volume (kg) per meter of
Indoor unit
refrigerant piping (liquid pipe ø6.35)
FDT, FDEN
0.02
FDU, FDUM, SRK
FDF 0.02
● This unit contains factory charged refrigerant covering 15m/8m of refrigerant piping and additional refrigerant charge on
the installation site is not required for an installation with up to 15m/8m refrigerant piping.
When refrigerant piping exceeds 15m/8m, additionally charge an amount calculated from the pipe length and the above
table for the portion in excess of 15m/8m.
● If an existing pipe system is used, a required refrigerant charge volume will vary depending on the liquid pipe size.
For further information, please see "5. UTILIZATION OF EXISTING PIPING."
Formula to calculate the volume of additional refrigerant required
Additional charge volume (kg) = { Main length (m) – Factory charged volume} x 0.02 (kg/m)
*When an additional charge volume calculation result is negative,
it is not necessary to charge refrigerant additionally.
● For an installation measuring 15m/8m or shorter in pipe length, please charge the refrigerant volume charged for shipment at the
factory, when you recharge refrigerant after servicing etc.
8) Heating and condensation prevention
(1) Dress refrigerant pipes (both gas and liquid pipes) for heat insulation and prevention of dew condensation.
·
Improper heat insulation/anti-dew dressing can result in a water leak or dripping causing damage to household effects, etc.
(2) Use a heat insulating material that can withstand 120 ℃ or a higher temperature. Poor heat insulating capacity can cause heat insulation problems or cable
deterioration.
·
All gas pipes must be securely heat insulated in order to prevent damage from dripping water that comes from the condensation formed on them during a cooling operation
or personal injury from burns because their surface can reach quite a high temperature due to discharged gas flowing inside during a heating operation.
·
Wrap indoor units' flare joints with heat insulating parts (pipe cover) for heat insulation (both gas and liquid pipes).
·
Give heat insulation to both gas and liquid side pipes. Bundle a heat insulating material and a pipe tightly together so that no gaps may be left between them and wrap them
together with a connecting cable by a dressing tape.
·
Both gas and liquid pipes need to be dressed with 20 mm or thicker heat insulation materials above the ceiling where relative humidity exceeds 70%.
3. DRAIN PIPING WORK
●
Execute drain piping by using a drain elbow and drain
Tightening angle ( ° )
Recommended length of a tool handle (mm)
45〜 6 0 150
14〜 1 8
34〜 4 2 30〜 4 5 200
49〜 6 1 30〜 4 5 250
68〜 8 2 15〜 2 0 300
Airtighteness test completed
Vacuuming begins
Run the vacuum pump for at least one hour after the vacuum
gauge shows -101kPa or lower. (-755mmHg or lower)
Vacuuming completed
Confirm that the vacuum gauge indicator does not rise even if
the system is left for one hour or more.
Vacuum gauge check
Fill refrigerant
Refrigerant volume charged for Installation's pipe length (m) covered
shipment at the factory (kg) without additional refrigerant charge
1.6 15
1.6 8
The screw of the side cover
is tightened securely.
Do not hold the valve cap area with a spanner.
Outdoor unit
Service Valve
Cap
Service Valve
(Liquid side)
-101kPa
(-755mmHg)
Handle Lo
Service Valve
(Gas side)
Service Valve
Cap
Check joint
Charge hose
(Designed specifically for R410A)
Securely tighten the service valve cap and the check joint blind nut after adjustment.
Service valve size Service valve cap
(mm) tightening torque (N·m)
ø6.35 (1/4") 20〜30
ø12.7 (1/2")
25〜35
Charging refrigerant
(2)
● Since R410A refrigerant must be charged in the liquid phase, you should charge it, keeping the container
cylinder upside down or using a refrigerant cylinder equipped with a siphon tube.
● Charge refrigerant always from the liquid side service port with the service valve shut. When you find it
difficult to charge a required amount, fully open the outdoor unit valves on both liquid and gas sides and
charge refrigerant from the gas (suction) side service port, while running the unit in the cooling mode. In
doing so, care must be taken so that refrigerant may be discharged from the cylinder in the liquid phase all
the time. When the cylinder valve is throttled down or a dedicated conversion tool to change liquid-phase
refrigerant into mist is used to protect the compressor, however, adjust charge conditions so that
refrigerant will gasify upon entering the unit.
● In charging refrigerant, always charge a calculated volume by using a scale to measure the charge volume.
When refrigerant is charged with the unit being run, complete a charge operation within 30 minutes.
●
Running the unit with an insufficient quantity of refrigerant for a long time can cause a compressor failure.
NOTE
Put down the refrigerant volume calculated from the pipe length onto the caution label attached on
the back side of the service panel.
Band (accessory)
Wires for connecting indoor
and outdoor units
Liquid piping
Use a torque wrench. If a torque wrench is
not available, fasten the flare nut manually
first and then tighten it further, using the
left table as a guide.
Gas side
service valve
Indoor unit
Check joint
Compound pressure gauge
Pressure gauge
Gauge Manifold
(Designed specifically for R410A)
Handle Hi.
Charge hose
(Designed specifically for R410A)
Vacuum pump adapter
(Anti-reverse flow type)
(Designed specifically for R410A)
Vacuum pump
Check joint blind nut
tightening torque (N·m)
10〜12
Pipe cover (accessory)
Exterior tape
Gas piping
Insulation
5. UTILIZATION OF
Check whether an existing p
START
Are an outdoor unit and an indoor unit c
existing pipe system to reuse?
YES
Are the existing units our prod
YES
Does the existing pipe system to reuse satisf
(1) The pipe length is 30m or less.
(2) The pipe size conforms to the table of pip
(3) The elevation difference between the indo
conforms to the following restrictions.
Where the outdoor unit is above: 15m o
Where the outdoor unit is below: 15m o
YES
Is the unit to install in the existing pi
twin-triple-double-twin model?
NO
Is the existing pipe system to reuse free of corr
NO
Is the existing pipe system to reuse free of g
(Check whether refrigerant charge was requ
the system before)
NO
Are there any branch pipes with no indoor
NO
Are heat insulation materials of the existing
reuse free of peel-offs or deterioration?
(Heat insulation is necessary for both gas an
NO
Aren't there any loose pipe sup
No loose pipe supports
The existing pipe system is