12 Operation
Installation and operation manual
26
RXYSQ6T7Y1B9
VRV IV-S system air conditioner
4P397285-1B – 2016.03
The following operation is performed in order to prevent the heating
capacity from dropping or cold air from blowing.
Defrost operation
In heating operation, freezing of the outdoor unit's air cooled coil
increases over time, restricting the energy transfer to the outdoor
unit's coil. Heating capability decreases and the system needs to go
into defrost operation to be able to deliver enough heat to the indoor
units.
The indoor unit will stop fan operation, the refrigerant cycle will
reverse and energy from inside the building will be used to defrost
the outdoor unit coil.
The indoor unit will indicate defrost operation on the displays
.
Hot start
In order to prevent cold air from blowing out of an indoor unit at the
start of heating operation, the indoor fan is automatically stopped.
The display of the user interface shows
. It may take some
time before the fan starts. This is not a malfunction.
12.2.4
To operate the system (WITHOUT cool/
heat changeover remote control switch)
1
Press the operation mode selector button on the user interface
several times and select the operation mode of your choice.
Cooling operation
Heating operation
Fan only operation
2
Press the ON/OFF button on the user interface.
Result:
The operation lamp lights up and the system starts
operating.
12.2.5
To operate the system (WITH cool/heat
changeover remote control switch)
Overview of the changeover remote control switch
a
b
a
FAN ONLY/AIR CONDITIONING
SELECTOR SWITCH
Set the switch to
for fan only
operation or to
for heating or
cooling operation.
b
COOL/HEAT CHANGEOVER SWITCH
Set the switch to
for cooling or to
for heating
To start
1
Select operation mode with the cool/heat changeover switch as
follows:
Cooling operation
Heating operation
Fan only operation
1
1
1
1
1
2
Press the ON/OFF button on the user interface.
Result:
The operation lamp lights up and the system starts
operating.
To stop
3
Press the ON/OFF button on the user interface once again.
Result:
The operation lamp goes out and the system stops
operating.
NOTICE
Do not turn off power immediately after the unit stops, but
wait for at least 5 minutes.
To adjust
For programming temperature, fan speed and air flow direction refer
to the operation manual of the user interface.
12.3
Using the dry program
12.3.1
About the dry program
▪ The function of this program is to decrease the humidity in your
room with minimal temperature decrease (minimal room cooling).
▪ The micro computer automatically determines temperature and
fan speed (cannot be set by the user interface).
▪ The system does not go into operation if the room temperature is
low (<20°C).
12.3.2
To use the dry program (WITHOUT cool/
heat changeover remote control switch)
To start
1
Press the operation mode selector button on the user interface
several times and select
(program dry operation).
2
Press the ON/OFF button of the user interface.
Result:
The operation lamp lights up and the system starts
operating.
3
Press the air flow direction adjust button (only for double-flow,
multi-flow, corner, ceiling-suspended and wall-mounted). Refer
to
"12.4 Adjusting the air flow direction" on page 27
To stop
4
Press the ON/OFF button on the user interface once again.
Result:
The operation lamp goes out and the system stops
operating.
NOTICE
Do not turn off power immediately after the unit stops, but
wait for at least 5 minutes.
