13 Special requirements for R32 units
Installation and operation manual
23
REMA5+REYA8~20A7Y1B
VRV 5 heat recovery
4P684060-1 – 2022.02
NOT OK
OK
Case
5
c
c
e
a
b
c
c
c
e
a
b
Group control is allowed up to a maximum of
5 indoor units connected to different ports or
connected to the same port. At least one R32
safety system compatible remote controller
should be in the room of the indoors.
6
c
c
c
e
a
b
c
c
c
e
a
b
All indoor units under group control need to be in
the same room.
7
c
e
c
e
f
g
a
b
In room: master remote controller in fully functional OR alarm only.
In supervisor room: supervisor remote controller
In particular situations it is mandatory to install a
remote controller at a supervised location
a
Outdoor unit
b
Branch selector (BS)
c
Indoor unit
d
Remote controller NOT compatible with R32 safety
system
e
Remote controller compatible with R32 safety system
f
Remote controller in supervisor mode
g
Supervisor room
13.3
About the charge limit
The charge limit must be determined separately for
each
BS
unit
branch pipe port
.
This is possible because of the shut-off valves in the BS unit. The
maximum amount of refrigerant that can escape in case of a leak is
determined by the piping length and indoor heat exchanger size.
This is directly linked to the downstream indoor unit capacity of this
piping section.
In case a leak is detected in an indoor unit, the shut-off valves in the
BS unit of the respective port will close. The piping section with the
leak is now shut off from the rest of the system and the amount of
refrigerant that can leak is significantly reduced.
Note:
In case 2 branch pipe ports are combined to a single branch
pipe port (e.g. FXMA200/250), they have to be considered as a
single branch pipe port.
13.4
To determine the charge limit
1
Determine the smallest room served per BS unit branch pipe
port in order to derive the maximum indoor capacity index that
can be connected in total per branch pipe port:
The room area can be determined by projecting the walls,
doors and partitions to the floor and calculate the enclosed
area. The area of the smallest room being served by a port of
the BS unit is used in the next step to determine the maximum
allowable indoor capacity that can be connected to that port.
Spaces connected by only false ceilings, ductwork, or similar
connections shall not be considered a single space.
If the partition between 2 rooms on the same floor meets
certain requirements then the rooms are considered as one
room and the areas of the rooms may be added up. In this way
it is possible to increase the A
min
value used to calculate the
maximum allowed charge.
One of the following 2 requirements must be met in order to
add up room areas.
▪ Rooms on the same floor that are connected with a
permanent opening that extends to the floor and is intended
for people to walk through can be considered as one room.
▪ Rooms on the same floor connected with openings that fulfil
following requirements can be considered as a single room.
The opening must consist out of 2 parts to allow for air
circulation.
A
nvmin
≥
20
mm
≥
50% A
nvmin
≤
100
mm
1500
mm
300
mm
200
mm
≥
20
mm
