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13. Servicing Mode
13.1 Pump Down Operation
• Operate the pump down according to the following
procedures.
1 Confirm the valve on the liquid side and gas
side is open.
2 Press PUMP DOWN switch (SW1) on the
display printed circuit board for more than 5
seconds. Pump down (cooling) operation is
performed for 15 minutes.
3 Set the liquid side 3 way valve to close
position and wait until the pressure gauge
indicates 1.45 PSI.
4 Immediately set the gas side valve to close
position and then press the PUMP DOWN
switch (SW1) to stop the pump down
operation.
Note: Pump down operation will stop
automatically after 15 minutes if PUMP
DOWN switch (SW1) is not pressed
again.
Pump down operation cannot be
restarted until 3 minutes after
compressor is stopped.
LED 2 3 4 5 Message
○ ○ ○ ○
Pump down operation progress
○ ○ ○
3 minutes before operation end
○ ○
2 minutes before operation end
○
1 minute before operation end
Status
Pump down operation end
○ : Flashing
13.2 Test Operation
• Test operation can be carried out using OPERATION TEST switch (SW2) on the display printed circuit board
inside the outdoor unit. For cooling test, press the TEST OPERATION switch (SW2) for more than 5 seconds.
LED 1 and LED 2 will illuminate when shift into cooling test operation.
13.3 Wiring Error Check
This product capable to correcting the wiring errors
automatically by following procedures.
1 Confirm the valve on the liquid side and gas
side is open.
2 Press WIRING CHECK switch (SW3) on the
display printed circuit board for more than 10
seconds to start wiring check operation.
3 Wiring check process will complete in
approximately 10 minutes. However, wiring
check operation will not start within 3 minutes
after compressor is stopped. When outdoor air
temperature is less than 41°F or unit has
abnormality, wiring check will not start. (See
NOTE 2).
The LED 2 to 6 in display printed circuit board inside
the outdoor unit indicate whether correction is possible
or not and the status of the correction, as shown in the
table below.
LED 2 3 4 5 6 Message
ROOM A B - - -
All flashing Automatic correction impossible
LED 2, 4, 6 and LED 3,
5 alternatively flashing
Wiring check in progress
Flashing one after
another
Automatic correction completed
Status
Other than above Unit has abnormally (Note 4)
If automatic correct is impossible, check the indoor
unit wiring and piping manually.
