Refrigerant Piping System - Mitsubishi Electric CITY MULTI PQHY-P200YHM-A Manuel D'installation

Warning:
When installing and moving the unit, do not charge the system with any
other refrigerant other than the refrigerant specifi ed on the unit.
- Mixing of a different refrigerant, air, etc. may cause the refrigerant cycle to
malfunction and may result in severe damage.
Caution:
• Use a vacuum pump with a reverse fl ow check valve.
- If the vacuum pump does not have a reverse fl ow check valve, the vacuum
pump oil may fl ow back into the refrigerant cycle and cause deterioration of
the refrigerant oil.
• Do not use the tools shown below used with conventional refrigerant.
(Gauge manifold, charge hose, gas leak detector, check valve,
refrigerant charge base, vacuum gauge, refrigerant recovery
equipment)
- Mixing of conventional refrigerant and refrigerant oil may cause the
refrigerant oil to deteriorate.
- Mixing of water will cause the refrigerant oil to deteriorate.
- R410A refrigerant does not contain any chlorine. Therefore, gas leak
detectors for conventional refrigerants will not react to it.
• Manage the tools used for R410A more carefully than normal.
- If dust, dirt, or water gets in the refrigerant cycle, the refrigerant oil will
deteriorate.
• Never use existing refrigerant piping.
- The large amount of chlorine in conventional refrigerant and refrigerant oil
in the existing piping will cause the new refrigerant to deteriorate.
• Store the piping to be used during installation indoors and keep both
ends of the piping sealed until just before brazing.
- If dust, dirt, or water gets into the refrigerant cycle, the oil will deteriorate
and the compressor may fail.
• Do not use a charging cylinder.
- Using a charging cylinder may cause the refrigerant to deteriorate.
• Do not use special detergents for washing piping.

9.2. Refrigerant piping system

Connection example
[Fig. 9.2.1] (P.4)
Heat source model
Gas side
Liquid pipe
Model number
The 1st branch of P450 ~ P650
Joint
4-Branching header (Downstream unit model total <= 200)
8-Branching header (Downstream unit model total <= 400)
10-Branching header (Downstream unit model total <= 650)
Heat source twinning kit
A Heat source unit
C Indoor unit
E Heat source twinning kit
*1 ø12.7 for over 90 m
*2 ø12.7 for over 40 m
*3 The pipe sizes listed in columns A1 to A3 in this table correspond to the sizes
for the models listed in the unit 1, 2, and 3 columns. When the order of the
models for unit 1, 2, and 3 change, make sure to use the appropriate pipe size.
[Fig. 9.2.2] (P.5)
Heat source model
Low-pressure side
Liquid pipe
Model number
Heat source twinning kit
Low-pressure gas pipe
A Heat source unit
C BC controller (main)
E Indoor unit (15 ~ 80)
G Heat source twinning kit
*1 The pipe sizes listed in columns A1 to A2 in this table correspond to the sizes
for the models listed in the unit 1 and 2 columns. When the order of unit 1 and
2 is changed, make sure to use the appropriate pipe size for the model.
Liquid side
Total capacity of indoor units
Gas pipe
Downstream unit model total
The 1st branch of P700, P750, P800
B First branch
D Cap
High-pressure side
Total capacity of indoor units
Gas pipe
Downstream unit model total
High-pressure gas pipe
B BC controller (standard)
D BC controller (sub)
F Indoor unit (100 ~ 250)
Precautions for heat source unit combinations
Refer to [Fig. 9.2.3] for the positioning of twinning pipes.
[Fig. 9.2.3] (P.7)
<A> When the piping on the heat source unit side (from the twinning pipe)
exceeds 2 m, ensure a trap (gas pipe only) within 2 m. Make sure the height
of the trap is 200 mm or more.
If there is no trap, oil can accumulate inside the pipe, causing a shortage of
oil and may damage the compressor. (for PQHY-P·YSHM-A)
<B> Pipe connection example (for PQHY-P·Y(S)HM-A)
A Indoor unit
Within 2 m
C
Pipes on site
E
Straight run of pipe that is 500 mm or more
G
Precautions for heat source unit combinations
Refer to [Fig. 9.2.4] for the positioning of twinning pipes.
[Fig. 9.2.4] (P.7)
<A> The piping from the heat source units to twinning pipe must be made to
slope downwards the twinning pipe. (both the liquid and the gas side for
PQHY-P·YSHM-A, the high-pressure side only for PQRY-P·YSHM-A)
<B> Slope of twinning pipes (for PQHY-P·YSHM-A)
Make sure the slope of the twinning pipes are at an angle within ±15° to the
horizontal plane.
If the slope exceeds the specifi ed angle, the unit may be damaged.
<C> Pipe connection example (for PQRY-P·YSHM-A)
A Downward slope
BC controller (standard or main)
C
Slope of the twinning pipe is at an angle within ±15° to the ground
E
Twinning pipe (low-pressure side)
F
On-site piping (low-pressure connecting pipe: between heat source units)
H
On-site piping (low-pressure main pipe: to BC controller)
I
On-site piping (high-pressure main pipe: to BC controller)
J
B Trap (gas pipe only)
Twinning pipe
D
Twinning kit
F
B Upward slope
Twinning pipe
D
Twinning pipe (high-pressure side)
G
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