Installation Of Unit; Installation; Connecting Direction For Refrigerant Piping; Refrigerant Piping Installation - Mitsubishi Electric CITY MULTI PUMY-P125YMA Installationshandbuch

6. Installation of unit

6.1. Installation

[Fig. 6.1.1] (P.3)
A M10 anchor bolt procured at the site.
• Fix unit tightly with bolts so that unit will not fall down due to earthquake or
gust.
• Use concrete or angle for foundation of unit.
• Vibration may be transmitted to the installation section and noise and vibration
may be generated from the floor and walls, depending on the installation con-
ditions. Therefore, provide ample vibrationproofing (cushion pads, cushion
frame, etc.).
Warning:
• Be sure to install unit in a place strong enough to withstand its weight.
Any lack of strength may cause unit to fall down, resulting in a personal
injury.
• Have installation work in order to protect against a strong wind and earth-
quake.

7. Refrigerant piping installation

Connecting the piping is a terminal-branch type in which refrigerant piping from
the outdoor unit is branched at the terminal and connected to each of the indoor
units.
For the piping of outdoor unit, flare connection must be used.
Note that the branched sections are brazed.
Warning:
Always use extreme care to prevent the refrigerant gas (R407C or R22) from
leaking while using fire or flame. If the refrigerant gas comes in contact with
the flame from any source, such as a gas stove, it breaks down and gener-
ates a poisonous gas which can cause gas poisoning. Never weld in an
unventilated room. Always conduct an inspection for gas leakage after in-
stallation of the refrigerant piping has been completed.

7.1. Caution

1 Use the following materials for refrigeration piping.
• Material: Use refrigerant piping made of phosphorus deoxidized copper.
In addition, be sure that the inner and outer surfaces of the pipes are clean
and free of hazardous sulphur, oxides, dust/dirt, shaving particles, oils,
moisture, or any other contaminant. (For R407C models)
2 Commercially available piping often contains dust and other materials. Always
blow it clean with a dry inert gas.
3 Use care to prevent dust, water or other contaminants from entering the piping
during installation.
4 Reduce the number of bending portions as much as possible, and make bend-
ing radius as big as possible.
5 Always observe the restrictions on the refrigerant piping (such as rated length,
the difference between high/low pressures, and piping diameter). Failure to do
so can result in equipment failure or a decline in heating/cooling performance.
6 The City Multi Series Y will stop due an abnormality due to excessive or insuf-
ficient coolant. At such a time, always properly charge the unit. When servic-
ing, always check the notes concerning pipe length and amount of additional
refrigerant at both locations, the refrigerant volume calculation table on the
back of the service panel and the additional refrigerant section on the labels
for the combined number of indoor units.
7 Use liquid refrigerant to fill the system.
8 Never use refrigerant to perform an air purge. Always evacuate using a vacuum
pump.
9 Always insulate the piping properly. Insufficient insulation will result in a de-
cline in heating/cooling performance, water drops from condensation and other
such problems.
0 When connecting the refrigerant piping, make sure the ball valve of the out-
door unit is completely closed (the factory setting) and do not operate it until
the refrigerant piping for the outdoor and indoor units has been connected, a
refrigerant leakage test has been performed and the evacuation process has
been completed.
A Always use a non-oxidizing brazing material for brazing the parts. If a non-
oxidizing brazing material is not used, it could cause clogging or damage to
the compressor unit.
B Never perform outdoor unit piping connection work when it is raining.
Any installation deficiency may cause unit to fall down, resulting in a
personal injury.
When building the foundation, give full attention to the floor strength, drain water
disposal <during operation, drain water flows out of the unit>, and piping and wir-
ing routes.
Bolt pitch for side-by-side arrangement of units.
[Fig. 6.1.2] (P.3)
6.2. Connecting direction for refrigerant pip-
ing
[Fig. 6.2.1] (P.3)
Warning:
When installing and moving the unit, do not charge it with refrigerant other
than the refrigerant specified on the unit.
- Mixing of a different refrigerant, air, etc. may cause the refrigerant cycle to mal-
function and result in severe damage.
Caution:
• Use a vacuum pump with the service port provided the outdoor unit's
stop valve.
- If the vacuum pump does not have the service port, the vacuum pump oil
may flow back into the refrigerant cycle and cause deterioration of the refrig-
erator oil and other trouble.
• Do not use the tools shown below used with conventional refrigerant.
(For R407C models)
(Gauge manifold, charge hose, gas leak detector, check valve, refriger-
ant charge base, vacuum gauge, refrigerant recovery equipment)
- Mixing of conventional refrigerant and refrigerator oil may cause the refrig-
erator oil to deteriorate.
- Mixing of water will cause the refrigerator oil to deteriorate.
- R407C refrigerant does not contain any chlorine. Therefore, gas leak detec-
tors for conventional refrigerants will not react to it.
• Manage the tools more carefully than normal. (For R407C models)
- If dust, dirt, or water gets in the refrigerant cycle, the refrigerator oil will dete-
riorate.
• Never use existing refrigerant piping. (For R407C models)
- The large amount of chlorine in conventional refrigerant and refrigerator 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. (For R407C models)
- Using a charging cylinder may cause the refrigerant to deteriorate.
• Do not use special detergents for washing piping.

7.2. Refrigerant piping system

Connection Example
[Fig. 7.2.1] (P.4)
Å Liquid pipe
Ç Total capacity of indoor units
‰ Branch Kit Model
Ì 8-Branching Header
A Outdoor Unit
C Indoor unit
ı Gas pipe
Î Model number
Ï 4-Branching Header
B First Branch
D Cap
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