218
20. Servicing Mode
OFF ON
OFF ON
Fig. 1
SW1 (PUMP DOWN)
SW2 (OPERATION TEST)
JP1
(COOL ONLY)
20.1.1 Pump Down Operation
Operate the pump down according to the following procedures.
1. Confirm all the 4pcs of 3-way valve on liquid and gas side are open.
2. Connect pressure gauge to gas side of 3-way valve for Duct unit (recommended).
3. 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.
4. Set the liquid side 3-way valve for Tank unit to close position followed by liquid side 3-ways valve for Duct
unit and wait until the pressure gauge indicates 0.01 MPa (0.1 k
g
/cm
2
G).
5. Immediately set the gas side 3-way valve for Tank unit to close position followed by gas side 3-way valve for
Duct unit 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 is not started within 3 minutes after compressor is stopped.
LED
2
3
4
5
Message
Status
○
○
○
○
Pump down operation progress
○
○
○
3 minutes before operation end
○
○
2 minutes before operation end
○
1 minute before operation end
Pump down operation end
○
: Flashing
Close
Hexagonal
wrench
Liquid shut-off valve
Gas shut-off valve
Valve lid
20.1.2 Test Run Operation
Test operation can be carried out using TEST OPERATION button (SW2) on the Service PCB inside the outdoor
unit.
For Cooling test, press the TEST OPERATION button (SW2) for 5 seconds or more but less than 10 seconds,
LED1 and LED 2 will illuminate when shift into cooling test operation.
For Heating test, press the TEST OPERATION button (SW2) for more than 10 seconds, LED 1 and LED 3 will
illuminate when shift into heating test operation.
Press the TEST OPERATION button (SW2) again to cancel test operation.
