14-3.Pump Down - Fujitsu GENERAL ARHG72LHTA Design & Technical Manual

14-3. Pump down
WARNING
• Never touch electrical components such as the terminal blocks except the button on the dis-
play board. It may cause a serious accident such as electric shock.
• During the pump-down operation, make sure that the compressor is turned off before you re-
move the refrigerant piping.
Do not remove the connection pipe while the compressor is in operation with 2-way or g. 3-
way valve open. This may cause abnormal pressure in the refrigeration cycle that leads to
breakage and even injury.
CAUTION
• Perform the pump down operation before disconnecting any refrigerant pipe or electric cable.
• Collect refrigerant from the service port or the 3-way valve if pump down cannot be per-
formed.
• In case of a group control system installation, do not turn the power off until pump down is
completed in all outdoor units.
(Group control system installation described in "SPECIAL INSTALLATION METHODS" in the
installation manual of the indoor unit.)
¢ Pump down procedure
Confirm that the power is off, and then open the service panel.
Symbols in the following table indicate LED status.
"○": Lights off, "●": Lights on
1. Check the 3-way valves (both the liquid side and gas side) are opened.
2. Turn the power on.
3. Press [PUMP DOWN] button for 3 seconds or more after 3 minutes after power on.
LED display lights on as shown in the above figure, and the fans and the compressor start
operating.
NOTE: If the [PUMP DOWN] button is pressed during compressor operation, the compres-
sor will stop, and the operation will start after about 3 min.
4. LED display will change as shown below about 3 minutes after the compressor starts. Fully
close the 3-way valve on the liquid pipe side at this stage.
NOTE: If the valve on the liquid pipe side is not closed, the pump down cannot be per-
formed.
PUMP
POWER
ERROR
DOWN
MODE (L1)
● ○ ○
PUMP
POWER
ERROR
DOWN
MODE (L1)
● ○ ●
PUMP
POWER
ERROR
DOWN
MODE (L1)
● ○ ●
- 81 -
LOW PEAK
NOISE CUT
(L2) (L3) (L4) (L5)
○ ○ ○ ○
LOW PEAK
NOISE CUT
(L2) (L3) (L4) (L5)
○ ○ ● ●
LOW PEAK
NOISE CUT
(L2) (L3) (L4) (L5)
○ ○ ○ ●
(L6)
○
(L6)
●
(L6)
●