Mitsubishi Electric MXZ-3C24NA Notice D'installation page 7

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 refriger-
ant. 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.
4-3. TEST RUN
Be sure to also check the following.
The outdoor unit is not faulty. When the outdoor unit fails, LED outdoor unit control panel
blinks.
Both the gas and liquid stop valves are completely open.
• 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 combi-
nation is difficult, use this function to detect and correct the combination by following the proce-
dures 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 detec-
tion, the indoor unit automatically stops operation. This is not a malfunction.
Stop valve
Union
Union
Indoor
unit
Union
Stop valve with
service port
Union
Refrigerant gas
cylinder
operating valve
Gauge manifold
(for R410A)
valve (for R410A)
Refrigerant gas cylinder for R410A with siphon
Refrigerant (liquid)
Electronic scale for refrigerant charging
LED
SW871
Liquid
pipe
Outdoor
unit
Gas
pipe
* D unit is for
4C36NA only.
Charge hose
(for R410A)
En-6