4 Preparation
Installation and operation manual
10
RWEYQ8~RWEYQ8~14T9Y1B
VRV IV water-cooled system air conditioner
4P452190-1A – 2017.04
▪ Concerning refnet headers, choose from the following table in
accordance with the total capacity of all the indoor units connected
below the refnet header.
Indoor unit capacity
index
2 pipes
3 pipes
<200
KHRQ22M29H
KHRQ23M29H
200≤x<290
290≤x<640
KHRQ22M64H
(a)
KHRQ23M64H
(a)
≥640
KHRQ22M75H
KHRQ23M75H
(a)
If the pipe size above the refnet header is Ø34.9 mm or
more, KHRQ22M75H is required.
INFORMATION
Maximum 8 branches can be connected to a header.
▪ How to choose an outdoor multi connection piping kit. Choose
from the following table in accordance with the number of outdoor
units.
Number of outdoor units
Branch kit name
2
BHFQ22P1007
3
BHFQ22P1517
INFORMATION
Reducers or T-joints are field supplied.
NOTICE
Refrigerant branch kits can only be used with R410A.
4.2.4
Multiple outdoor units: Possible layouts
▪ The piping between the outdoor units must be routed level or
slightly upward to avoid the risk of oil retention into the piping.
Pattern 1
a
b
Pattern 2
a
b
a
b
a
b
a
To indoor unit
b
Piping between outdoor units
X
Not allowed (oil remains in piping)
O
Allowed
▪ If the piping length between the outdoor unit connecting pipe kit or
between the outdoor units exceeds 2 m, create a rise of 200 mm
or more in the gas line within a length of 2 m from the kit.
▪ For the gas piping (both discharge and suction gas piping in case
of the heat recovery system) after the branch, install a trap of
200 mm or more using the piping included in the piping kit for
connecting the outdoor unit. Otherwise, the refrigerant may stay in
the piping, causing damage to the outdoor unit.
≥200 mm
If
Then
≤2 m
≤2 m
b
a
>2 m
≤2 m
≤2 m
≥200 mm
≥200 mm
>2 m
>2 m
b
a
a
To indoor unit
b
Piping between outdoor units
NOTICE
There are restrictions on the refrigerant pipe connection
order between outdoor units during installation in case of a
multiple outdoor unit system. Install according to following
restrictions. The capacities of outdoor units A, B and C
must fulfill the following restriction conditions: A≥B≥C.
a
c
b
A
B
C
a
To indoor units
b
Outdoor unit multi connecting piping kit (first branch)
c
Outdoor unit multi connecting piping kit (second branch)
4.3
Preparing water piping
4.3.1
Water circuit requirements
NOTICE
In case of plastic pipes, make sure they are fully oxygen
diffusion tight according to DIN 4726. The diffusion of
oxygen into the piping can lead to excessive corrosion.
▪
Connecting piping – Legislation.
Make all piping connections in
accordance with the applicable legislation and the instructions in
the "Installation" chapter, respecting the water inlet and outlet.
▪
Connecting piping – Force.
Do NOT use excessive force when
connecting the piping. Deformation of the piping can cause
malfunctioning of the unit.
▪
Connecting piping – Tools.
Only use appropriate tooling to
handle brass, which is a soft material. If NOT, pipes will get
damaged.
▪
Connecting piping – Stainless steel.
Only use stainless steel
material to connect the water piping to the unit. If NOT, pipes will
get corroded. Take preventive measures, for example by
insulating the connection on the water pipe.
▪
Connecting piping – Air, moisture, dust.
If air, moisture or dust
gets into the circuit, problems may occur. To prevent this:
▪ Only use clean pipes
▪ Hold the pipe end downwards when removing burrs.
▪ Cover the pipe end when inserting it through a wall, to prevent
dust and/or particles entering the pipe.
▪ Use a decent thread sealant to seal connections.
▪
Piping work
–
Dripping
. The outdoor unit is intended for indoor
installation. Carry out piping work in such a way that no water
drips on the outdoor unit.
▪
Outlets.
Do NOT connect the
drain
outlet to the
water
outlet.
