16
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Piping installation
Installer and user reference guide
80
R R8T7V1B
VRV IV heat pump for indoor installation
4P499898-1B – 2021.12
Manifold
Connections
Compressor unit
p< p>
R410A
N2
g
h
e
f
i
B
A
Circuit 1 and 2 together
C
c
b
A
a
d
B
C
C
C
D
D
RDXYQ
RDXYQ
c
c
d
d
b
b
a
a
5 HP
8 HP
Only circuit 1
a
B
b
A
C
C
Only circuit 2
C
C
d
B
c
A
a
Liquid line stop valve (circuit 1: to heat exchanger unit)
b
Gas line stop valve (circuit 1: to heat exchanger unit)
c
Gas line stop valve (circuit 2: to indoor units)
d
Liquid line stop valve (circuit 2: to indoor units)
e
Vacuum pump
f
Pressure reducing valve
g
Nitrogen
h
Weighing scales
i
Refrigerant R410A tank (siphon system)
A, B, C
Valves A, B and C
D
Refrigerant line splitter
Valve
State of valve
Valves A, B and C
Open
Liquid line and gas line stop valves (a, b,
c, d)
Close
NOTICE
The connections to the indoor units and to the heat exchanger unit, and all indoor
units and the heat exchanger unit itself should also be leak and vacuum tested. Keep
any possible (field supplied) field piping valves open as well.
Refer to the indoor unit installation manual for more details. Leak test and vacuum
drying should be done before the power supply is set to the unit. If not, see also the
flow chart earlier described in this chapter (see
78]).
16.3.4 To perform a leak test
The leak test must satisfy the specifications of EN378‑2.
To check for leaks: Vacuum leak test
1
Evacuate the system from the liquid and gas piping to –100.7 kPa (–1.007 bar)
(5 Torr absolute) for more than 2 hours.
2
Once reached, turn off the vacuum pump and check that the pressure does
not rise for at least 1 minute.
3
Should the pressure rise, the system may either contain moisture (see vacuum
drying below) or have leaks.
To check for leaks: Pressure leak test
1
Test for leaks by applying a bubble test solution to all piping connections.
