Additional Refrigerant Charge - Mitsubishi Electric DXK09ZJ-S Technical Manual

adjusting the measurement of protrusion B with a protrusion control gauge.
• The pipe should be anchored every 1.5m or less to isolate the vibration.
• Tighten a flare joint securely.
Do not apply force beyond proper fastening torque in tightening the flare nut.
CAUTION
Fix both liquid and gas operation valves at the valve main bodies as illustrated on the right, and then fasten them,
applying appropriate fastening torque.
Operation valve size (mm) Tightening torque (N·m)
ø6.35 (1/4") 14
ø9.52 (3/8") 34
ø12.7 (1/2") 49
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 0.5MPa, and then stop. Leave it for five minutes to see if the pressure drops.
b) Then raise the pressure to 1.5MPa, and stop. Leave it for five more minutes to see if the pressure drops.
c) Then raise the pressure to the specified level (4.15MPa), 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 C, the pressure also fall approximately 0.01MPa. 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>
Air tightness test completed
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 (Model 18)
(1) Calculate a required refrigerant charge volume from the following table.
Additional charge volume (kg) Refrigerant volume charged
per meter of refrigerant piping for shipment at the factory
(liquid pipe ø6.35)
Model 18 0.02
• 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.
Formula to calculate the volume of additional refrigerant required
Additional charge volume (kg) = { Main length (m) – Factory charged volume 15 (m) } 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 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
Tightening angle ( ) Recommended length of a tool handle (mm)
~ ~
18 45 60 150
~ ~
42 30 45 200
~ ~
61 30 45 250
Vacuuming begins
Run the vacuum pump for at least one hour after the vacuum
gauge shows –0.1MPa or lower. (–76cmHg 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
Installation's pipe length (m)
covered without additional
(kg) refrigerant charge
1.35 15
ø9.52
side cover is
ø12.7
tightened securely.
Do not hold the valve cap area with a spanner.
Outdoor unit
Operation valve cap
Operation valve
(two-way valve)
-0.1MPa
(-76cmHg)
Handle Lo
Operation valve
(three-way valve)
Operation valve cap
Check joint Charge hose (Designed specifically for R410A)
Securely tighten the operation valve cap and the check joint blind nut after adjustment.
Operation valve size Operation valve cap
(mm) tightening torque (N·m)
ø6.35 (1/4")
~
20 30
ø9.52 (3/8")
~
ø12.7 (1/2") 25 35
(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 30minutes.
Running the unit with an insufficient quantity of refrigerant for a long time can cause a compressor failure.
Put down the refrigerant volume calculated from the pipe length onto the caution label attached
NOTE
on the service panel.
~ ~
0 0.5 1.0 1.5
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
operation 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
Band (accessory)
Pipe cover (accessory)
Electrical installation work
• Do not use any supply c
• braided cord (code de
• ordinary tough rubber
• flat twin tinsel cord (c
Use polychloroprene sh
• Ground the unit. Do not
If improperly grounded,
• A grounding wire must
• The installation of an im
such as an electric shoc
• Do not turn on the powe
• Do not use a condensive
abnormal overheat accid
• For power supply cables
• Do not lay electronic co
the malfunctioning or a
• Fasten cables so that m
• When cables are connec
terminal connection and
penetrates into the box.
• Never use a shield cable
INSTALLAT