Specifications

RXYQQ8~20T7Y1B
VRV IV System Air Conditioner
4P345099-1 – 2013.04
Installation and operation manual
47
17.3. Service mode operation
Refrigerant recovery operation/vacuuming operation is possible by
applying setting [2-21]. Refer to "13.2. Operating the push buttons
and DIP switches on the logic board" on page 29 for details how to
set mode 2.
When vacuuming/recovery mode is used, check very carefully what
should be vacuumed/recovered before starting. See installation
manual of the indoor unit for more information about vacuuming and
recovery.
17.3.1. Vacuuming method
1 When the unit is at standstill, set the unit in [2-21]=1.
2 When confirmed, the indoor and outdoor unit expansion valves
will fully open.
At that moment the segment display indication=t.01 and the user
interface of all indoor units indicate TEST (test operation) and
(external control) and the operation will be prohibited.
3 Evacuate the system with a vacuum pump.
4 Press BS3 to stop vacuuming mode.
17.3.2. Refrigerant recovery operation method
This should be done by a refrigerant reclaimer. Follow the same
procedure as for vacuuming method.
18. Caution for refrigerant leaks
18.1. Introduction
The installer and system specialist shall secure safety against
leakage according to local regulations or standards. The following
standards may be applicable if local regulations are not available.
This system uses R410A as refrigerant. R410A itself is an entirely
safe non-toxic, non-combustible refrigerant. Nevertheless care must
be taken to ensure that air conditioning facilities are installed in a
room which is sufficiently large. This assures that the maximum
concentration level of refrigerant gas is not exceeded, in the unlikely
event of major leak in the system and this in accordance to the local
applicable regulations and standards.
18.2. Maximum concentration level
The maximum charge of refrigerant and the calculation of the
maximum concentration of refrigerant is directly related to the
humanly occupied space in to which it could leak.
The unit of measurement of the concentration is kg/m
3
(the weight in
kg of the refrigerant gas in 1 m
3
volume of the occupied space).
Compliance to the local applicable regulations and standards for the
maximum allowable concentration level is required.
According to the appropriate European Standard, the maximum
allowed concentration level of refrigerant to a humanly space for
R410A is limited to 0.44 kg/m
3
.
1 Direction of the refrigerant flow
2 Room where refrigerant leak has occurred (outflow of all
the refrigerant from the system)
Pay special attention to places, such as basements etc., where
refrigerant can stay, since refrigerant is heavier than air.
18.3. Procedure for checking maximum concentration
Check the maximum concentration level in accordance with steps 1
to 4 below and take whatever action is necessary to comply.
1 Calculate the amount of refrigerant (kg) charged to each system
separately.
2 Calculate the volume of the room (m
3
) where the indoor unit is
installed.
In a case such as the following, calculate the volume of (A), (B)
as a single room or as the smallest room.
A Where there are no smaller room divisions:
B Where there is a room division, but there is an opening
between the rooms sufficiently large to permit a free flow of
air back and forth.
1 Opening between the rooms
2 Partition
(Where there is an opening without a door or where there
are openings above and below the door which are each
equivalent in size to 0.15% or more of the floor area.)
3 Calculating the refrigerant density using the results of the
calculations in steps 1 and 2 above.
If the result of the above calculation exceeds the maximum
concentration level, a ventilation opening to the adjacent room
shall be made.
NOTICE
Play it safe. For protection of the PCB, touch the switch
box casing by hand in order to eliminate static electricity
from your body before performing service.
2
1
Amount of
refrigerant in a
single unit system
(amount of
refrigerant with
which the system
is charged before
leaving the factory)
+
Additional charging
amount (amount of
refrigerant added
locally in
accordance with
the length or
diameter of the
refrigerant piping)
=
Total
amount of
refrigerant
(kg) in the
system
NOTICE
Where a single refrigerant facility is divided into 2 entirely
independent refrigerant systems, use the amount of
refrigerant with which each separate system is charged.
Total volume of refrigerant in
the refrigerant system
≤
Maximum concentration
level (kg/m
3
)
Size (m
3
) of smallest room in
which there is an indoor unit
installed
1
2