5 User interface
Installation and operation manual
9
RWEYQ8~14T9Y1B
VRV IV water-cooled system air conditioner
4P452190-1D – 2020.10
h
High temperature (HT) Hydrobox unit
i
EKEXV kit
j
Air handling unit (AHU)
k
User interface
l
Wireless user interface
m
Water system connection
Water system
c
g
d
f
e
b
a
a
Unit
b
Connection to refrigerant system
c
Water piping
d
Dry cooler
e
Brine loop
f
Closed cooling tower
g
Boiler
5
User interface
CAUTION
▪ NEVER touch the internal parts of the controller.
▪ Do NOT remove the front panel. Some parts inside are
dangerous to touch and appliance problems may
happen. For checking and adjusting the internal parts,
contact your dealer.
This operation manual offers a non-exhaustive overview of the main
functions of the system.
Detailed information on required actions to achieve certain functions
can be found in the dedicated installation and operation manual of
the indoor unit.
Refer to the operation manual of the installed user interface.
6
Operation
6.1
Operation range
Use the system in the following temperature and humidity ranges for
safe and effective operation.
Cooling
Heating
Indoor temperature
21~32°C DB
14~25°C WB
15~27°C DB
Water temperature
10~45°C
Water temperature – extended
range (in case brine type setting
[2-50] is set for brine)
–10~45°C
Indoor humidity
≤80%
(a)
(a)
To avoid condensation and water dripping out of the unit. If the
temperature or the humidity is beyond these conditions, safety
devices may be put in action and the air conditioner may not
operate.
Above operation range is only valid in case direct expansion indoor
units are connected to the VRV IV system.
Special operation ranges are valid in case of using Hydrobox units or
AHU. They can be found in the installation/operation manual of the
dedicated unit. Latest information can be found in the technical
engineering data.
6.2
Operating the system
6.2.1
About operating the system
▪ Operation procedure varies according to the combination of
outdoor unit and user interface.
▪ To protect the unit, turn on the main power switch 6 hours before
operation.
6.2.2
About cooling, heating, fan only, and
automatic operation
▪ Changeover cannot be made with a user interface whose display
shows
"change-over under centralised control" (refer to
installation and operation manual of the user interface).
▪ When the display
"change-over under centralised control"
flashes, refer to
"6.5.1 About setting the master user
11].
▪ The fan may keep on running for about 1 minute after the heating
operation stops.
▪ The air flow rate may adjust itself depending on the room
temperature or the fan may stop immediately. This is not a
malfunction.
6.2.3
About the heating operation
It may take longer to reach the set temperature for general heating
operation than for cooling operation.
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 remove frost from the outdoor
unit’s coil. During defrost operation the heating capacity on the
indoor unit side will temporarily drop until defrosting is completed.
After defrosting, the unit will regain its full heating capacity.
In case of
Then
RWEYQ16~42 multi-
models
The indoor unit will continue heating
operation at a reduced level during defrost
operation. It will guarantee a decent comfort
level indoor.
RWEYQ8~14 single
models
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 display
.
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.
6.2.4
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.
