Mitsubishi Heavy Industries FDCW100VNX-A, Technical Manual

Page: 72 / 315

Installation
'19 • HM-T-340
3. DRAIN PIPING WORK
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.
Gas side
service valve
Check joint
Pressurize
Close
Outdoor unit Indoor unit
＜
Work flow
＞
6) Evacuation
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.
Airtighteness test completed
Fill refrigerant
Vacuum gauge check
Vacuuming completed
Vacuuming begins
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.
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.
Wires for connecting indoor
and outdoor units
Exterior tape
Gas piping
insulation
Liquid piping
Band
Pipe cover
8) Insulation on piping
(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.
- 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%.
7) Additional refrigerant charge
(1) Calculate a required refrigerant charge volume from the following table.
(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 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.
●
To charge refrigerant again to the system, recover refrigerant from the system first and then charge the same volume as initial charge.
NOTE
●
Write down the addifional and total refrigerant volume on the label in front.
● Do not use drain elbow and grommet made of plastic for drain piping when base heater for outdoor unit is used.
Plastic grommet and elbow will be damaged and burnt in worst case.
● Prepare another drain tray made of metallic material for collecting drain when base heater is used.
● In case plastic grommet and drain elbow is used in warm climate area, disconnet the connector for heater on
PCB shown in the drawing.
● 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.
●
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
option part) or concrete blocks.
●
Connect a drain elbow as shown in the illustration and close the other two drain holes with grommets.
Drain elbow ( 1 pc.)
Drain grommet
( 2 pcs.)
Hard vinyl chloride pipe for general purpose (VP16)
CNF
100VNX. 140VNX 71VNX
CNN
Formula to calculate the volume of additional refrigerant required
71VNX
100VNX
140VNX
Additional charge volume (kg) per meter of refrigerant piping (liquid pipe
φ
9.52
)
0.06
0.06
0.06
Refrigerant volume charged for shipment at the factory (kg)
2.55
2.9
4.0
Installation’s pipe length (m) covered without additional refrigerant charge
15
15
15
● This unit contains factory charged refrigerant covering 15m of refrigerant piping and additional refrigerant charge on the installation site is not required for an installation with up to 15m refrigerant piping.
When refrigerant piping exceeds 15m, additionally charge an amount calculated from the pipe length and the above table for the portion in excess of 15m.
Additional charge volume (kg) = { Main pipe length (m) – Length covered without additional charge 15 (m) } x 0.06 (kg/m)
*When an additional charge volume calculation result is negative, it
is not necessary to charge refrigerant additionally.
How to remove the service panel
(100VNX, 140VNX only) 71VNX
140VNX
100VNX
First remove the screw (s) ( mark) of the service panel or the side cover and push it
down into the direction of the arrow mark and then remove it by pulling it toward you.
● Take care so that installed pipes may not touch components within a unit. If touching with
an internal component, it will generate abnormal sounds and/or vibrations.
●
The pipe can be laid in any of the following directions: side right, front, rear and downward. (100VNX, 140VNX)
● Remove a knock-out plate provided on the pipe penetration to open a minimum necessary area and attach an edging
material supplied as an accessory by cutting it to an appropriate length before laying a pipe. (100VNX, 140VNX)
●
Carry out the on site piping work with the service valve fully closed.
● Give sufficient protection to a pipe end (compressed and blazed, or with an adhesive tape) so that water or foreign matters
may not enter the piping.
●
Bend a pipe to a radius as large as practical.(R100 〜 R150) Do not bend a pipe repeatedly to correct its form.
●
Flare connection is used between the unit and refrigerant pipe. Flare a pipe after engaging a flare nut onto it. Flare
dimensions for R410A are different from those for conventional R407C. Although we recommend the use of flaring
tools designed specifically for R410A, conventional flaring tools can also be used by adjusting the measurement of
protrusion B with a protrusion control gauge.
4) On-site piping work
IMPORTANT
A B
Flared pipe end: A (mm)
φ 6.35
φ 9.52
φ
12.7
φ 15.88
Copper
pipe outer
diameter
0
ー 0 ． 4
Ａ
9 ． 1
13 ． 2
16.6
19.7
Copper pipe protrusion for flaring: B (mm)
φ 6.35
φ 9.52
φ 12.7
φ
15.88
Copper
pipe outer
diameter
In the case of a rigid (clutch) type
With an R410A tool With a conventional tool
0 〜 0.5 0.7 〜 1.3
For downward connection
For side right connection
For front connection
For rear connection
CAUTION
Do not apply force beyond proper fastening
torque in tightening 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.
Tightening angle
( ° )
Tightening torque
(N-m)
φ 6.35 (1/4")
φ 9.52 (3/8")
φ 12.7 (1/2")
φ 15.88 (5/8")
14 〜 18
34 〜 42
49 〜 61
68 〜 82
45
〜
60
30 〜 45
30 〜 45
15 〜 20
150
200
250
300
● Tighten a flare joint securely with a double spanner.
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.
Recommended length
of a tool handle (mm)
Service valve size
(mm)
Do not hold the valve cap area with a spanner.
Screw
Side cover
Catch
Catch
Outdoor unit installation
- 70 -
#