Bosch CLIMATE 5000 VRF RDCI Series Installation Manual page 12

12 | REFRIGERANT PIPE
CAUTION
• Pressurised nitrogen (3.9MPa; 40kgf/cm
testing.
• Prior to connecting vacuum pump, ensure you release all the
nitrogen from all three pipes.
•
Only Nitrogen can be used for pressure testing. Do not use any other
substances.
•
Ensure the shut off valves are protected during brazing.
•
A Torr gauge must be used to measure the vacuum state.
5.11 Triple vacuum process
1) Vacuum from all three ports down to 2Torr.
2) Break vacuum with nitrogen to absorb moisture. Then repeat vacuum
process down to 1.6Torr.
3) Break Vacuum for with nitrogen to absorb moisture. Repeat vacuum
to achieve 1.5 Torr or lower.
Connect manifold gauges and vacuum pump to all three pipe connections.
Perform vacuum until for minimum of 2 hours.
Shut off vacuum pump and pressure with nitrogen to absorb moisture.
Repeat vacuum process for a further two hours.
Shut off vacuum pump and break vacuum for with nitrogen to absorb moisture.
Repeat vacuum process for a further 2 hours and achieve a minimum
of 1.5Torr.
If 1.5Torr cannot be achieved, repeat re-pressure and find leak.
Into the vacuum state
Re-peat Triple Vacuum process.
Perform a triple evacuation
CAUTION
Do not add refrigerant when nitrogen is present. Do not mix
■
refrigerants.
Do not use refrigerant for air vacuuming.
■
Before adding refrigerant leave the system on a vacuum for 2 hours
■
to see if the gauges rise. If the gauges rise please repeat strength/
tightness test and check for leaks.
5.12 Refrigerant amount to be added
1) Calculate the added refrigerant according to the diameter and the
length of the liquid side pipe. The refrigerant is R410A.
Note:
1. Assume equivalent pipe length of the branching pipe header to be
0.5m.
2. The refrigerant amount to be added of SBOX02 is 0.3kg/per,
of SBOX04/SBOX06 is 0.5kg/per.
6 720 862 437 (2016/10)
) is used for strength
2
Table.5-9
Pipe size on liquid
side
Ø6.4
Ø9.5
Ø12.7
Ø15.9
Ø19.1
Ø22.2
Ø25.4
Ø28.6
2) Add the additional quantity of calculated refrigerant from the low-
pressure pipe and liquid pipe.
5.13 The Key points of installing connective pipe-
work between cascaded outdoor units
1) When connecting the outdoor units, the pipes should be installed
horizontally (Fig5-7, Fig 5-8). It is not permitted to use method
shown in Fig 5.9.
2) All connective pipework between the outdoor units are not to be
installed above the outlets of the condenser. See Fig. 5.10..
√ Correct way
√ Correct way
× Wrong way
RDCI Series – All DC Inverter Outdoor Units
Refrigerant to be
added per meter
0.023kg
0.060kg
0.120kg
0.180kg
0.270kg
0.380kg
0.550kg
0.710kg
Fig. 5-7
Fig. 5-8
Fig. 5-9