62
8-9. Refrigerant collecting (pump down)
1. Start and end of pump
down operation
Control modes
Remarks
Control details
1-1. Requirements for starting
Pump down operation will be conducted when SWP on the outdoor controller
board is turned on while the unit is being stopped.
1-2. Requirements for ending
Pump down operation will end if any of the following conditions is satisfied.
a. Low pressure switch has been used.
b. 3 minutes have passed since the pump down operation started.
c. Operation has been stopped by remote controller or changed to the other
mode except COOL.
d. Error has been detected.
2-1. Following controls are activated during pump down operation.
• Compressor control
The same continuous operation as COOL operation regardless of intake
temperature.
• LEV(A) control
Opening pulse is fixed to step 3 (480 pulse).
• LEV(B) control
Completely closed (0 pulse).
• Fan control
Fan step is fixed to step 10.
• Four way valve
OFF in COOL operation.
w
Low pressure
switch mentioned
in (a) is equipped
in RP4 to 6 only.
2. During pump down
operation
1
Pump down operation is considered to be finished normally when the ending
condition (a) or (b) is satisfied.
At this time, the outdoor controller board’s LED1 (green) turns OFF and LED2
(red) turns ON. The units cannot be operated until the power is reset.
(To prevent the units from operating with pump down operation.)
2
If the pump down operation ends due to the ending conditions (c) or (d), the unit
will be in a state of normal stop.
To prevent the
unit from
operating with
pump down
operation.
<Complementary
explanation for
above 2 controls>
OCT04A-3.qxp 04.9.29 9:16 AM Page 62
