Shut-Off Valves - Daikin VRV 5 RXYA8A7Y1B Installer And User Manual

16.4.4 Shut-off valves

About the charge limit
To determine the charge limit
RYMA5+RXYA8~20A7Y1B
VRV 5 heat pump
4P749918-1 – 2023.12
In case shut-off valves are required as a safety measure, SV unit which has shut-off
valves needs to be installed to reduce the amount of refrigerant leakage in to the
room where the indoor unit is installed.
For installation of the SV unit, refer to the installation and operation manual
delivered with the SV unit.
The maximum amount of charge limit and so the maximum capacity class of indoor
unit which is allowed to install in the room is determined as below.
The charge limit must be determined separately for each SV unit branch pipe port.
This is possible because of the shut-off valves in the SV 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 SV 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: When two branch pipe ports are combined in order to form a single branch
pipe port (e.g. FXMA200/250), they must be considered as a single branch pipe
port.
Step 1 – In order to derive the total refrigerant charge limit in the system,
determine the area
▪ of the rooms where an indoor unit is installed,
▪ AND of the area of the rooms served by a ducted indoor unit installed in a
different room.
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 SV 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.
Step 2 – Use the table below to determine the maximum total indoor unit capacity
(sum of all connected indoor units) that is allowed for a single SV unit branch pipe
port. In case a ducted indoor unit is serving a different room than where it is
installed, the restrictions of the room area apply to both the indoor installation
room as the conditioned room separately. Supply and return air shall be directly
ducted to that room.
Area of installed/conditioned
room [m²]
1 indoor unit per branch pipe
<5
5
6
7
8
9
10
16 Special requirements for R32 units
|
Maximum total indoor unit capacity class
2~5 indoor units per branch pipe port
(a)
port
40 m after 1
— —
10 —
25 —
32 —
40 —
71 —
80 —
st (b) st
branch 90 m after 1 branch
—
—
—
—
—
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Installer and user reference guide
(c)
77