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4-2. GAS CHARGE
Perform gas charge to unit.
1) Connect gas cylinder to the service port of stop valve.
2) Perform air purge of the pipe (or hose) coming from refrigerant gas cylinder.
3) Replenish specified amount of the refrigerant, while operating the air conditioner for cooling.
Note:
In case of adding refrigerant, comply with the quantity specified for the refrigerating cycle.
CAUTION:
When charging the refrigerant system with additional refrigerant, be sure to use liquid refrigerant.
Adding gas refrigerant may change the composition of the refrigerant in the system and affect
normal operation of the air conditioner. Also, charge the liquid refrigerant slowly, otherwise the
compressor will be locked.
To maintain the high pressure of the gas cylinder, warm the gas cylinder with warm water (under
104°F (40°C)) during cold season. But never use naked fire or steam.
Union
Stop valve
Liquid
pipe
Indoor
unit
Stop valve with
service port
Gas
pipe
Refrigerant gas
cylinder
operating valve
(for R410A)
Gauge manifold
valve (for R410A)
Charge hose
(for R410A)
Refrigerant gas cylinder for R410A with siphon
Electronic scale for refrigerant charging
Refrigerant (liquid)
Outdoor
unit
Union
Union
Union
Model
Indoor unit
NTXMMX20A122A
✱
A
–
B
4-3. REMOVING THE MAINTENANCE PANEL
The setting of Dip Switch on the outdoor controller board can be changed
without removing the front panel.
Follow the procedures below to remove the maintenance panel and set
the Dip Switch.
1) Remove screw(s) which fix the maintenance panel.
2) Remove the maintenance panel, and perform necessary settings.
3) Install the maintenance panel.
Note:
Make sure to fix the maintenance panel securely. Incomplete installation
could cause malfunction.
Maintenance panel
4-4. TEST RUN
• Test runs of the indoor units should be performed individually. See the installation manual coming with the indoor unit, and make sure all the units operate properly.
• If the test run with all the units is performed at once, possible erroneous connections of the refrigerant pipes and the indoor/outdoor unit connecting wires cannot be
detected. Thus, be sure to perform the test run one by one.
About the restart protective mechanism
Once the compressor stops, the restart preventive device operates so the compressor will not operate for 3 minutes to protect the air conditioner.
Wiring/piping correction function
This unit has a wiring/piping correction function which corrects wiring and piping combination. When there is possibility of incorrect wiring and piping combination,
and confirming the combination is difficult, use this function to detect and correct the combination by following the procedures below.
Make sure that the following is done.
• Power is supplied to the unit.
• Stop valves are open.
Note:
During detection, the operation of the indoor unit is controlled by the outdoor unit. During detection, the indoor unit automatically stops operation. This is not a mal-
function.
4-5. EXPLANATION TO THE USER
• Using the OPERATING INSTRUCTIONS, explain to the user how to use the air conditioner (how to use the remote controller, how to remove the air filters, how to
remove or put the remote controller in the remote controller holder, how to clean, precautions for operation, etc.).
• Recommend the user to read the OPERATING INSTRUCTIONS carefully.
Procedure
Press the piping/wiring correction switch (SW871) 1 minute or more after turning on the power
supply.
• Correction completes in 10 to 15 minutes. When the correction is completed, its result is shown
by LED indication. Details are described in the following table.
• To cancel this function during its operation, press the piping/wiring correction switch (SW871)
again.
• When the correction completed without error, do not press the piping/wiring correction switch
(SW871) again.
When the result is “Not completed”, press the piping/wiring correction switch (SW871) again to
cancel this function. Then, confirm the wiring and piping combination in a conventional manner by
operating the indoor units one by one.
• The operation is done while the power is supplied. Make sure not to contact parts other than
the switch, including the P.C. board. This may cause electric shock or burn by hot parts and
live parts around the switch. Contacting the live parts may cause P.C. board damage.
• To prevent electronic control P.C. board damage, make sure to perform static elimination before
operating this function.
• This function does not operate when the outside temperature is 0°C or below.
LED indication during detection:
LED1
(Red)
LED2
(Yellow)
LED3
(Green)
Lit
Lit
Once
Result of piping/wiring correction function
LED1
(Red)
LED2
(Yellow)
LED3
(Green)
Result
Lit
Not lit
Lit
Completed
(Problem corrected or
normal)
Once
Once
Once
Not completed
(Detection failed)
Other indications
Refer to “SAFETY PRE
-
CAUTIONS WHEN LED
BLINKS” located behind
the top panel.
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