NO.
Item
Specification outline
Remarks
8
Cooling oil
(refrigerant)
recovery control
Heating
refrigerant (oil)
recovery
control
Defrosting
control
Short
intermittent
operation
compensation
control
Elimination of
residual heat
While the outdoor unit is recovering cooling oil (refrigerant), the indoor
units perform the following control tasks:
[common for operational (cooling thermo
stat
ON / thermo
stat
OFF / FAN),
as
well as nonoperational indoor units]
1) Open the indoor PMV to a certain degree.
2) Engage in recovery control for a specified period of time and return
to normal cooling operation at the end of this period upon
terminating the control.
3) Operate the drain pump throughout the recovery control period and
for about 1 minute after it.
While the outdoor unit is recovering heating refrigerant (oil), the indoor
units perform the following control tasks:
1) Open the indoor PMV to a certain degree.
2) Control the indoor fan according to the operation mode.
[Indoor units operating in heating thermo ON / OFF state]
Let the indoor fan continue operating, but turn it off if the temperature
of the indoor heat exchanger drops.
[Indoor units operating in FAN mode]
Turn off the indoor fan and display “HEATING STANDBY ” on the
remote control.
[Non-operational indoor units]
Keep the indoor fan turned off.
3) Terminate the recovery operation depending on the TC2
temperature reading.
The timing of termination is determined by each indoor unit.
4) Operate the indoor fan and drain pump for about 1 minute after the
termination of the recovery operation. (Applicable to compact 4-way
cassette type and 1- way cassette type)
• Recovery operation
normally takes
place roughly every
2 hours.
• The opening
position of the
indoor PMV
depending on the
type and capacity
of the indoor unit.
• Recovery
operation
normally takes
place roughly
every hour.
• The opening
position of the
indoor PMV
depending on the
type and capacity
of the indoor unit.
9
While the outdoor unit is engaged in defrosting control, the indoor units
perform the following control tasks:
1) Open the indoor PMV to a certain degree.
2) Control the indoor fan according to the operation mode.
[Indoor units operating in heating thermo ON / OFF state]
Let the indoor fan continue operating for a while, but turn it off as the
temperature of the indoor heat exchanger drops.
[Indoor units operating in FAN mode]
Let the indoor fan continue operating.
[Non-operational indoor units]
Keep the indoor fan turned off.
3) As defrosting control comes to an end, it gives way to heating
refrigerant (oil) recovery control.
(For control details, see “9. Heating refrigerant (oil) recovery control” above.)
• For defrosting
commencement
conditions, see 5
Control Outline “
7
.
Defrosting control
(reverse defrosting
method)” in SMMS-
e
Outdoor Unit
Service Manual
SVM-
16039
above.
• The opening
position of the
indoor PMV
depending on the
type and capacity
of the indoor unit.
10
11
1. For 5 minutes after startup, the system is forced to continue operating
even if it reaches the thermo OFF region.
2. However, priority is given to cooling / heating selection, operation
standby, and protective control, so that there is no overriding of
thermo OFF in these cases.
1
2
1. When the air conditioner is turned off after engaging in heating operation,
the indoor fan is operated for about 30 seconds in “breeze” mode.
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