Specifications

Installation and operation manual
56
RXYQQ8~20T7Y1B
VRV IV System Air Conditioner
4P345099-1 – 2013.04
Three main operation methods are available:
 Basic
The refrigerant temperature is fixed independent from the situation. It
corresponds to the standard operation which is known and can be
expected from/under previous VRV systems.
 Automatic
The refrigerant temperature is set depending on the outdoor ambient
conditions. As such adjusting the refrigerant temperature to match
the required load.
E.g., when your system is operating in cooling, you do not need as
much cooling under low outdoor temperatures (e.g., 25°C) as under
high outdoor temperatures (e.g., 35°C). Using this idea, the system
automatically starts increasing its refrigerant temperature,
automatically reducing the delivered capacity and increasing the
system's efficiency.
 Hi-sensible
The refrigerant temperature is set higher (cooling) compared to basic
operation. The focus under high sensible mode is comfort feeling for
the customer.
The selection method of indoor units is important and has to be
considered as the available capacity is not the same as under basic
operation. For details concerning to Hi-sensible applications, please
contact your installer.
Available comfort settings
For each of above modes a comfort level can be selected. It is related
to the timing and the effort (energy consumption) which is put in
achieving a certain room temperature by temporarily changing the
refrigerant temperature to different values:
 Powerful
 Quick
 Mild
 Eco
8. Maintenance
8.1. Maintenance after a long stop period (e.g., at the
beginning of the season)
 Check and remove everything that might be blocking inlet and
outlet vents of indoor units and outdoor units.
 Clean air filters and casings of indoor units
(8)
. Refer to the
operation manual supplied with the indoor units for details on
how to proceed and make sure to install cleaned air filters back
in the same position.
 Turn on the power at least 6 hours before operating the unit in
order to ensure smoother operation. As soon as the power is
turned on, the user interface display appears.
8.2. Maintenance before a long stop period (e.g., at the
end of the season)
 Let the indoor units run in fan only operation for about half a day
in order to dry the interior of the units. Refer to "6.1. Cooling,
heating, fan only, and automatic operation" on page 53 for
details on fan only operation.
 Turn off the power. The user interface display disappears.
 Clean air filters and casings of indoor units
(8)
. Refer to the
operation manual supplied with the indoor units for details on
how to proceed and make sure to install cleaned air filters back
in the same position.
9. Symptoms that are not air conditioner
troubles
Following symptoms are not air conditioner troubles:
Symptom 1: The system does not operate
 The air conditioner does not start immediately after the ON/OFF
button on the user interface is pressed. If the operation lamp
lights, the system is in normal condition. To prevent overloading
of the compressor motor, the air conditioner starts 5 minutes
after it is turned ON again in case it was turned OFF just before.
The same starting delay occurs after the operation mode
selector button was used.
 If "Under Centralized Control" is displayed on the user interface,
pressing the operation button causes the display to blink for a
few seconds. The blinking display indicates that the user
interface cannot be used.
 The system does not start immediately after the power supply is
turned on. Wait one minute until the micro computer is prepared
for operation.
Symptom 2: Cool/Heat cannot be changed over
 When the display shows (change-over under centralized
control), it shows that this is a slave user interface.
 When the cool/heat changeover remote control switch is
installed and the display shows (change-over under
centralized control), this is because cool/heat changeover is
controlled by the cool/ heat changeover remote control switch.
Ask your dealer where the remote control switch is installed.
CAUTION
Pay attention to the fan.
It is dangerous to inspect the unit while the fan is running.
Be sure to turn off the main switch before executing any
maintenance task.
(8) Contact your installer or maintenance person to clean air filters
and casings of the indoor unit. Maintenance tips and
procedures for cleaning are provided in the
installation/operation manuals of dedicated indoor units.