Panasonic CS-MC90KA / CU-MC180KA / CS-MC90KA / CU-3MC200KA / CS-MC120KA / CU-MC240KA Service Manual ▷ View online
– 32 –
MAC9902014C3
CS-MC90KA
2 Pumping down
Procedure:
(1) Confirm that both the 3-way valve are set to the
open position.
●
Remove the valve stem caps and confirm that the valve
stems are in the raised position.
stems are in the raised position.
●
Be sure to use a hexagonal wrench to operate the valve
stems.
stems.
(2) Operate the unit for 10 to 15 minutes.
(3) Stop operation and wait for 3 minutes, then
connect the charge set to the service port of the
3-way valves.
3-way valves.
●
Connect the charge hose with the push pin to the gas
side service port.
side service port.
(4) Air purging of the charge hose.
●
Open the low-pressure valve on the charge set slightly to
purge air from the charge hose.
purge air from the charge hose.
(5) Set the Liquid side 3-way valve to the closed
position.
(6) Operate the air conditioner at the cooling cycle
and stop it when the gauge indicates 0 kg/cm
2
G.
●
If the unit cannot be operated at the cooling
(weather is rather cool), press the Pump Down switch on
the Indoor unit.
(weather is rather cool), press the Pump Down switch on
the Indoor unit.
●
So that the unit can be operated.
(7) Immediately set the 3-way valve to the closed
position.
●
Do this quickly so that the gauge ends up indicating
1 to 3 kg/cm
1 to 3 kg/cm
2
G.
(8) Disconnect the charge set, and mount both the
3-way valve’s stem nuts and the service port cap.
●
Use torque wrench CWHAD-9211 to tighten the service
port nut to a torque of 1.8 N•m.
port nut to a torque of 1.8 N•m.
●
Be sure to check for gas leakage.
Purge the air
(Indoor unit)
(Liquid side)
(Gas side)
CLOSED
CLOSED
Lo
Hi
3-way valve
Closed
Open
3-way valve
(Outdoor unit)
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CS-MC90KA
MAC9902014C3
2-1 Re-air purging
(Re-installation)
Procedure:
(1) Remove the cap nut from 3-way valves.
●
Remove the cap nut from 3-way valves after carefully
checked whether the piping connection was properly
and certainly done.
checked whether the piping connection was properly
and certainly done.
(2) Confirm that the valve in both 3-way valve
are set to the CLOSED.
(3) Connect the gas cylinder to the liquid-side (high-
pressure) 3-way valve and the charge set to the
gas side (low-pressure) 3-way valve.
gas side (low-pressure) 3-way valve.
●
Remove the flare nut from the service port to connect the
charge set and gas cylinder.
charge set and gas cylinder.
●
Close the valves on the gas cylinder and charge set.
(4) Air purging.
●
Open the valve on the gas cylinder.
●
Open the valve on the charge set, discharge for three
seconds and wait for one minute. Repeat this three
times.
seconds and wait for one minute. Repeat this three
times.
(5) Check for gas leakage.
●
Check the flare connections for gas leakage.
(6) Discharge the refrigerant.
●
Close the valve on the gas cylinder and discharge
the refrigerant until the gauge indicates 3 to 5 kg/cm
the refrigerant until the gauge indicates 3 to 5 kg/cm
2
G.
(7) Disconnect the charge set and the gas
cylinder.
(8) Mount the valve stem cap nuts and the flare nuts
for service port onto the 3-way valves.
(9) Mount the cap nut and service port nut onto the
3-way valves.
●
Be sure to use a torque wrench (CWHAD-9211) to
tighten the service port nut.
tighten the service port nut.
●
Be sure to check for gas leakage.
Charging cylinder
(Indoor unit)
(Outdoor unit)
(Gas side)
3-way valve
3-way valve
(Liquid side)
Lo
Hi
Closed
Open
OPEN
CLOSED
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MAC9902014C3
CS-MC90KA
2-2 Balance refrigerant of the 3-way valves
(Gas leakage)
Procedure:
(1) Confirm that both the 3-way valve are set to the
open position.
(2) Connect the charge set to the Gas side 3-way
valve’s port.
●
Leave the valve on the charge set closed.
●
Connect the charge hose with the push pin to the
service port.
service port.
(3) Open the valves (Lo side) on the charge set and
discharge the refrigerant until the gauge indicates
0kg/cm
0kg/cm
2
G.
●
If there is no air in the refrigeration cycle [the pressure
w h e n t h e a i r c o n d i t i o n e r i s n o t r u n n i n g i s
higher than 1kg/cm
w h e n t h e a i r c o n d i t i o n e r i s n o t r u n n i n g i s
higher than 1kg/cm
2
G], discharge the refrigerant
until the gauge indicates 0.5 to 1kg/cm
2
G. If this is the
case, it will not be necessary to apply a evacuation.
●
Discharge the refrigerant gradually; if it is
discharged too suddenly, the refrigeration oil will
also be discharged.
discharged too suddenly, the refrigeration oil will
also be discharged.
(Outdoor unit)
3-way valve
(Indoor unit)
(Liquid side)
(Gas side)
3-way valve
Lo
Hi
OPEN
CLOSED
Open
Open
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CS-MC90KA
MAC9902014C3
3 Evacuation
(No refrigerant in the refrigeration cycle)
Procedure:
(1) Connect the vacuum pump to the charge set’s
center hose.
(2) Evacuation for approximately one hour.
●
Confirm that the gauge needle has moved toward
–76 cmHg [vacuum of 4 mmHg or less].
–76 cmHg [vacuum of 4 mmHg or less].
(3) Close the valve (Lo side) on the charge set, turn
off the vacuum pump, and confirm that the gauge
needle does not move (approximately
5 minutes after turning off the vacuum pump).
needle does not move (approximately
5 minutes after turning off the vacuum pump).
(4) Disconnect the charge hose from the vacuum
pump.
●
Vacuum pump oil.
If the vacuum pump oil becomes dirty or depleted,
replenish as needed.
If the vacuum pump oil becomes dirty or depleted,
replenish as needed.
3-way valve
3-way valve
OPEN
Vacuum pump
Lo
Hi
OPEN
(Indoor unit)
(Outdoor unit)
(Gas side)
(Liquid side)
Open
Open
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