Mitsubishi Heavy Industries MHI FDU71VNXVF1 Technical Manual page 240

with a protrusion control gauge.
●
The pipe should be anchored every 1.5m or less to isolate the vibration.
●
Tighten a flare joint securely with a double spanner.
Do not apply force beyond proper fastening torque in tightening
CAUTION
the flare nut.
Fix both liquid and gas service valves at the valve main bodies as illustrated
on the right, and then fasten them, applying appropriate fastening torque.
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 operation valve's check joint equipped on the
outdoor unit side. While conducting a test, keep the operation 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
＜Work 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.
7) Additional refrigerant charge
(1) Calculate a required refrigerant charge volume from the following table.
<Single type>
Additional charge volume (kg)
Pipe length for
Item
Standard refrigerant
standard refrigerant per meter of refrigerant piping
charge volume (kg)
Capacity charge volume (m) (liquid pipe)
Model 100V
Model 125V
2.0 0
Model 140V
●
A standard refrigerant charge volume means a refrigerant charge volume for an installation with 0m long refrigerant piping.
●
This unit contains factory charged refrigerant covering 30m of refrigerant piping and additional refrigerant charge on the installation site is not required for an installation with up to 30m refrigerant piping.
When refrigerant piping exceeds 30m, additionally charge an amount calculated from the pipe length and the above table for the portion in excess of 30m.
●
When refrigerant piping is shorter than 3m, reduce refrigerant by 1kg from the factory charged volume and adjust to 2.8kg.
●
If an existing pipe system is used, a required refrigerant charge volume will vary depending on the liquid pipe size. For further information, see "6. UTILIZATION OF EXISTING PIPING."
Formula to calculate the volume of additional refrigerant required
Additional charge volume (kg) = { Main pipe length (m) – Length covered without additional charge 30 (m) } x 0.06 (kg/m) + Total length of branch pipes (m) x 0.06 (kg/m)
Model 100〜140V
●
To charge refrigerant again, recover refrigerant from the system first and then charge the volume calculated from the above table (Standard refrigerant charge volume + branch pipes charge volume)
(2) Charging refrigerant
●
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 operation 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.
8) Heating and condensation prevention
(1) Dress refrigerant pipes (both gas and liquid pipes) for heat insulation and prevention of dew condensation.
(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.
- Improper heat insulation/anti-dew dressing can result in a water leak or dripping causing damage to household effects, etc.
- 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.
- Although it is verified in a test that this air conditioning unit shows satisfactory performance under JIS condensation test conditions, 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 grommets supplied separately as
optional parts, where water drained from the outdoor unit is a problem.
4. ELECTRICAL WIRING WORK
Electrical installation work must be performed by an electrical installation service provider qualified by a power provider of the country.
Electrical installation work must be executed according to the technical standards and other regulations applicable to electrical
installations in the country.
Do not use any supply cord lighter than one specified in parentheses for each type below.
●
- braided cord (code designation 60245 IEC 51),
- ordinary tough rubber sheathed cord (code designation 60245 IEC 53)
Operation valve size Tightening torque
(mm) (N-m)
φ6.35 (1/4")
14〜18
φ9.52 (3/8")
34〜42
φ12.7 (1/2")
49〜61
φ15.88 (5/8")
68〜82
Run the vacuum pump for at least one hour after the vacuum gauge shows
-101kPa or lower. (-755mmHg or lower)
Confirm that the vacuum gauge indicator does not rise even if the system is
left for one hour or more.
Installation's pipe length (m)
Refrigerant volume
charged for shipment covered without additional
at the factory (kg) refrigerant charge
0.06 3.8 30
Drain elbow ( 1 pe.)
Hard vinyl chloride pipe for general purpose (VP-16)
For details of electrical cabling, refer to the indoor unit installation manual.
φ12.7
16.6
φ15.88
19.7
Tightening angle Recommended length Do not hold the valve cap area with a spanner.
of a tool handle (mm)
(° )
45〜60 150
Use a torque wrench. If a torque wrench is not available,
30〜45 200
fasten the flare nut manually first and then tighten it
30〜45 250
further, using the left table as a guide.
15〜20 300
Airtighteness test completed
Pay attention to the following points in addition to the above for
Vacuuming begins
the R410A and compatible machines.
○To prevent a different oil from entering, assign dedicated tools, etc. to each
Vacuuming completed
refrigerant type. Under no circumstances must a gauge manifold and a charge
hose in particular be shared with other refrigerant types (R22, R407C, etc.).
Vacuum gauge check
○Use a counterflow prevention adapter to prevent vacuum pump oil from
entering the refrigerant system.
Fill refrigerant
<Twin, triple, W-twin type>
Additional charge volume (kg)
Item
Pipe length for
per meter of refrigerant piping
Standard refrigerant
standard refrigerant
(liquid pipe)
charge volume (kg)
charge volume (m)
Capacity Main pipe Branch pipe
Model 100V
Model 125V
2.0 0 0.06
Model 140V
*When an additional charge volume calculation result is negative,
it is not necessary to charge refrigerant additionally.
○
There are 3 drain holes provided on the bottom plate of an outdoor unit to discharge
condensed water.
○
When condensed water needs to be led to a drain, etc., install the unit on a flat base
(supplied separately as an optional part) or concrete blocks.
○
Connect a drain elbow as shown in the illustration and close the other two drain holes
with grommets.
Drain grommet
( 2 pes.)
Do not turn on the power until the electrical work is completeted .
●
Do not use a condensive capacitor for power factor improvement under any circumstances. (It dose not improve power factor,
●
while it can cause an abnormal overheat accident)
For power supply cables, use conduits.
●
Do not lay electronic control cables (remote control and signaling wires) and other cables together outside the unit. Laying them
●
φ12.7
φ15.88
Gas side
Outdoor unit operation valve Indoor unit
Check joint
Refrigerant volume Installation's pipe length (m)
charged for shipment covered without additional
at the factory (kg) refrigerant charge
3.8
30
Band (accessory)
Pipe cover (accessory)
Wires for connecting indoor
Exterior tape
and outdoor units
Gas piping
Liquid piping
insulation
5. TEST RUN
●
Before
WARNING
●
Turn o
●
In cas
●
Alway
●
Remo
Take u
●
When
CAUTION
●
You ca
● The 4
●
When
off. I
may o
1) Test run meth
(1) A test run can be initi
setting.
(2) Switching SW3-3 to O
(3) The unit will start a coolin
(4) Do not fail to switch
2) Checking the s
Use check joints provided
outdoor unit for checking di
As indicated in the table sh
depending on whether a c
3) Setting SW3-1
(1) Defrost control switchi
・ When this switch is t
・ Set this switch to O
heating operation.
(2) Snow guard fan contro
・ When this switch is tu
lower and the compre
・ When the unit is used
4) Failure diagnos
Error indicated on the Printed circui
remote control unit
Red L
E34 Blinking
E40 Blinking
Blinking
E49
● If an error code other
5) The state of th
The following table illus
Valve for a cooling operation
Valve for a heating operation
6) Heed the follow
This outdoor unit may st
level in the compressor fr
6. UTILIZATIO
Check whether an existing pipe
Are an outdoor unit an
existing pipe system t
Are the exist
Does the existing pipe s
(1) The pipe length is 50
(2) The pipe size conform
(3) The elevation differen
conforms to the follo
Where the outdoor
Where the outdoor
Is the unit to install in
twin-triple-double-twi
Is the existing pipe syste
Is the existing pipe syst
(Check whether refrige
the system before)
Are there any branch p