Panasonic CS-MZ20UD3EA Service Manual ▷ View online
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13.6.3 Relocation
1. Removing the air conditioning unit
a) Recovery of outdoor unit refrigerant by pumping down
Press “forced cooling button” (as a general rule, since 1998 the name of cooling testing button is changed,
and this name is unified within the air conditioning industry), and then you are able to start cooling operation
in which the room temperature is low, and you can recover the refrigerant from the outdoor unit.
1. Check the valve stems of two-way and three-way valves are open by being turned to anti-clockwise
and this name is unified within the air conditioning industry), and then you are able to start cooling operation
in which the room temperature is low, and you can recover the refrigerant from the outdoor unit.
1. Check the valve stems of two-way and three-way valves are open by being turned to anti-clockwise
(Remove the caps, and confirm the bars are fully open. Use hexagon wrench <4 mm> to open and close
the valves).
the valves).
2. Press the “Emergency Operation” button of the indoor units for five seconds and release [Forced cooling
operation] (for old models, press “forced cooling” button). Then, operate the air conditioning unit for about
10 minutes.
10 minutes.
3. Turn the stem of the two-way valve to the clock-wise and close the valve.
4. After about 2 ~ 3 minutes, turn the stem of the three-way valve quickly to the clock-wise, and stop the
4. After about 2 ~ 3 minutes, turn the stem of the three-way valve quickly to the clock-wise, and stop the
operation.
Caution: In the pump down operation, stop the compressor before removing the refrigerant pipes.
If you do not stop the compressor operation, and if the valve is open and remove the refrigerant pipes, the air
may be sucked into the system and causes extreme high temperature in the refrigerant cycle. This may result in
rupture or injury, etc.
If you do not stop the compressor operation, and if the valve is open and remove the refrigerant pipes, the air
may be sucked into the system and causes extreme high temperature in the refrigerant cycle. This may result in
rupture or injury, etc.
5. Attach and tighten the caps of two-way and three-way valves with torque wrench.
6. Remove the connecting pipes (liquid side and gas side).
6. Remove the connecting pipes (liquid side and gas side).
b) Removal of indoor and outdoor units
1. Remove the connecting pipes and wires between the indoor and outdoor units.
2. Attach capping flare nuts on the edges of the pipes, connecting the indoor and outdoor units, in order to
prevent dust and moisture get into the pipes.
3. Remove the indoor and outdoor units.
2. Unit
installation
Use new refrigerant pipes for the installation, and perform air purging using vacuum pump and gas
leakage testing stated in 14.5.1.
leakage testing stated in 14.5.1.
13.6.4 Replacement of air conditioning units and evacuation (when re-using the existing
pipes)
When replacing the air conditioning units, you might use the existing pipes, but it is recommended to perform flaring
again. In case of unit replacement, even if the unit is new refrigerant air conditioner, if the refrigerant oil is different, it
may cause problem. Further, when re-using the existing refrigerant pipes, it is recommended to evacuate the pipes
as much as possible, due to the reason that much refrigerant oil may be attached on the surface of the pipes. If the
pipes are used without evacuation, the remaining refrigerant oil may cause under-performance and abnormal
refrigerant cycle caused by non-compatibility of those oils.
again. In case of unit replacement, even if the unit is new refrigerant air conditioner, if the refrigerant oil is different, it
may cause problem. Further, when re-using the existing refrigerant pipes, it is recommended to evacuate the pipes
as much as possible, due to the reason that much refrigerant oil may be attached on the surface of the pipes. If the
pipes are used without evacuation, the remaining refrigerant oil may cause under-performance and abnormal
refrigerant cycle caused by non-compatibility of those oils.
13.6.5 Inter-changeability of refrigerant
Do not operate air conditioning units inserting wrong (or mixed) refrigerant (R22, R410A, R32). It may cause mal-
function of the units, and at the same time, may cause serious incident such as rupture of the refrigerant cycle.
function of the units, and at the same time, may cause serious incident such as rupture of the refrigerant cycle.
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13.6.6 Re-insertion of refrigerant in service
When re-insertion is needed, follow the procedures to ensure the insertion of new refrigerant at correct amount.
1. Attach charging hose (blue) to the service port of the outdoor unit.
2. Attach charging hose (red) to the vacuum pump. Fully open the 2-way and 3-way valves.
3. Place the refrigerant cylinder on the digital scale for refrigerant charging and connect the charge hose (yellow) to
1. Attach charging hose (blue) to the service port of the outdoor unit.
2. Attach charging hose (red) to the vacuum pump. Fully open the 2-way and 3-way valves.
3. Place the refrigerant cylinder on the digital scale for refrigerant charging and connect the charge hose (yellow) to
the connection port of the vacuum pump and the digital scale. Leave the cylinder valve fully open.
4. Fully open the handles Lo and Hi of the manifold gauge, and switch on the vacuum pump, and then perform
evacuation for at or more than one hour.
5. Confirm the compound gauge of -0.1 MPa (-76cmHg) and fully open the handles of Lo and Hi, and switch off the
vacuum pump. Leave it for about 1 ~ 2 minutes and confirm the needle of the compound gauge does not turn
back.
Refer to the picture below to follow the procedures below.
back.
Refer to the picture below to follow the procedures below.
6. Remove the charging hose (red) of the manifold gauge from the vacuum pump adopter.
7. After adjusting the digital scale to zero, open the cylinder valve and the valve Lo of the manifold gauge, and
7. After adjusting the digital scale to zero, open the cylinder valve and the valve Lo of the manifold gauge, and
insert the refrigerant.
8. If it is not possible to insert the refrigerant at regulated amount at once, operate the cooling mode and gradually
insert the refrigerant (recommended amount approx. 150 g / 1 time)
*Do not insert much refrigerant at once.
*Do not insert much refrigerant at once.
9. Close the open/close valve and insert the refrigerant in the charging hose to the outdoor unit.
*Perform this procedure during operating cooling operation. Close the stem of the two-way valve, and when the
pressure of the manifold gauge becomes zero (0), quickly remove the charging hose (blue). Immediately open
the 2-way valve, and stop the cooling operation.
pressure of the manifold gauge becomes zero (0), quickly remove the charging hose (blue). Immediately open
the 2-way valve, and stop the cooling operation.
10. Final checking • • • Confirm the 2-way and 3-way valves are fully open.
Attach the caps of the service port and control valve, and then check the gas leakage around the caps.
(Liquid side)
(Indoor unit)
(Outdoor unit)
(Gas side)
Two-way
valve
Open
Open
Three-way
valve
Hi
Lo
Vacuum
pump
adaptor
Vacuum
pump
Vacuum pump
charging hose
Electronic scale
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13.7 Repairing of refrigerant cycle / Brazing point
13.7.1 Preparation for repairing of refrigerant cycle / brazing
Brazing which is a technique needed for repairing refrigerant cycle requires advanced technique and experience, and
this brazing procedure can only be performed by the workers who completed “Gas Welding Skill Training” regulated
by the Occupational Safety and Health Act, and went through the training programs of refrigerant operations.
Dismantling and re-connecting (assembling) refrigerant system requires working space, and the space has to ensure
good air flow and fire prevention (water bucket and fire extinguisher). Moreover, the worker has to ensure the
wearing of goggles, grabs, safety shoes, and long sleeve shirts, and be aware of work safety and attempt to prevent
secondary defect (quality assurance of products). For brazing the indoor / outdoor unit structural components (heat
exchangers, compressors, expansion valves, four-way valve blocks), after the recovery of all refrigerant, confirm that
no refrigerant remains in the system, and fully open the 2-way and 3-way valves. When the brazing is conducted
outside, check and make sure no refrigerant is contained in the air (be careful with vaporized refrigerant).
Furthermore, protect the compressor terminal with metal plates, and heat but use wet clothes to cool down (releasing
the heat) the expansion valves, and four way valves (prevent destruction of parts). In brazing, it is important to pour
the brazing material without melting the base metal based on capillary action principle. In case of holes and oxidizing
caused by overheating, do not perform re-brazing or alteration but replace the parts.
this brazing procedure can only be performed by the workers who completed “Gas Welding Skill Training” regulated
by the Occupational Safety and Health Act, and went through the training programs of refrigerant operations.
Dismantling and re-connecting (assembling) refrigerant system requires working space, and the space has to ensure
good air flow and fire prevention (water bucket and fire extinguisher). Moreover, the worker has to ensure the
wearing of goggles, grabs, safety shoes, and long sleeve shirts, and be aware of work safety and attempt to prevent
secondary defect (quality assurance of products). For brazing the indoor / outdoor unit structural components (heat
exchangers, compressors, expansion valves, four-way valve blocks), after the recovery of all refrigerant, confirm that
no refrigerant remains in the system, and fully open the 2-way and 3-way valves. When the brazing is conducted
outside, check and make sure no refrigerant is contained in the air (be careful with vaporized refrigerant).
Furthermore, protect the compressor terminal with metal plates, and heat but use wet clothes to cool down (releasing
the heat) the expansion valves, and four way valves (prevent destruction of parts). In brazing, it is important to pour
the brazing material without melting the base metal based on capillary action principle. In case of holes and oxidizing
caused by overheating, do not perform re-brazing or alteration but replace the parts.
13.7.2 Adjustment
of vacuum pump pressure
1. Cylinder with adjustment handle
1. Check and confirm the adjustment handle of the 1
st
pressure adjuster is loosen (anticlockwise). If cylinder
valve is opened when the 1
st
gauge pressure adjust handle is closed, the 2
nd
gauge might get broken.
2. Open the cylinder valve, and check the remaining amount with the first t side pressure gauge.
3. Check the pressure of 2
3. Check the pressure of 2
nd
gauge and turn the adjustment handle to clock-wise direction to adjust the
pressure.
◎
◎
Oxygen 2
nd
side gauge pressure・・・・・・・・・・0.5 MPa (5.0 kgf / cm
2
)
◎
Propane 2
nd
side gauge pressure・・・・・・・0.05 MPa (0.5 kgf / cm
2
)
The primary gauge
(High pressure)
The secondary gauge
(Low pressure)
The secondary gauge
(Low pressure)
Adjustment
handle
Adjustment
handle
Oxygen regulator
Propane regulator
Main valve
Main valve
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2. Cylinder without adjustment valve
2
nd
side gauge pressure is adjusted by the adjuster.
Check the both side valves of the torch and open the cylinder valve to check the remaining refrigerant in the
cylinder.
Caution: Do not attach oil component on the connection port of the adjuster.
Especially, use an oxygen cylinder adjuster which is no oil substance type. Do not dismantle or repair the
adjuster and pressure gauge.
cylinder.
Caution: Do not attach oil component on the connection port of the adjuster.
Especially, use an oxygen cylinder adjuster which is no oil substance type. Do not dismantle or repair the
adjuster and pressure gauge.
13.7.3 Checking of gas provision
Checking there is no fire around the torch, and then confirm the provision of gas.
1. Slightly open the “propane valve” of the torch, and make sure the gas comes out from the torch crater and then
1. Slightly open the “propane valve” of the torch, and make sure the gas comes out from the torch crater and then
close the “propane valve”.
2. Slightly open the “oxygen valve” of the torch and make sure the gas comes out from the torch crater and then
close the “oxygen valve”.
Check there is no gas leakage around the hose connection.
Check there is no gas leakage around the hose connection.
13.7.4 Adjustment
of
flame
1. Slightly open the “propane valve” of the torch and lit with spark lighter.
This moment, the flame is only by propane and the color is red.
2. Gradually open the “oxygen valve” of the torch to mix oxygen, and adjust the amount of propane and oxygen with
the valve to make the flame suitable for brazing work.
If the white core flame splits into two, the torch crater might be clogged. In this case, remove the crater from the
torch and check.
If the white core flame splits into two, the torch crater might be clogged. In this case, remove the crater from the
torch and check.
Propane tank
(Gray)
Oxygen tank
(Black)
Black hose
Orange hose
Regulator
Regulator
Main valve
Main valve
Fuel gauge
0~25 MPa
(0~250 k
gf / cm²)
Fuel gauge
0~3 MPa
(0~30 k
gf / cm²)
Oxygen (Black hose)
Propane (Orange hose)
Propane valve
Oxygen valve
Nozzle
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