Precautions Concerning Piping Connection And Valve Operation - Mitsubishi Electric City Multi PQRY-P400YGM-A Installationshandbuch

The total length of each liquid line is as follows:
ø22.2: A = 40 m
ø12.7: C + D = 10 + 10 = 20 m
ø9.52: B + b + e + f = 10 + 5 + 10 + 10 = 35 m
ø6.35: a + c + d + g + h = 10 + 10 + 10 + 5 + 5 = 40 m
Therefore,
<Calculation example>
Additional refrigerant charge
= 40 × 0.23 + 20 × 0.12 + 35 × 0.06 + 40 × 0.024 + 3.0 + 2.0 + 2.0 = 21.7 kg
Value of α1
Total capacity of connecting indoor units
to Model 80
Models 81 to 160
Models 161 to 330
Models 331 to 480
Models 481 to 630
Models 631 to 710
Models 711 to 890
Value of α2
BC controller (main only)
BC controller (sub) connected (one)
BC controller (sub) connected (two)
Value of α3
PQRY-P400YSGM-A
PQRY-P500YSGM-A
9.2. Precautions concerning piping connec-
tion and valve operation
• The compressor unit is charged with refrigerant at factory shipment, but the
heat exchanger unit is not. (The heat exchanger unit is charged with inert gas.)
• Conduct piping connection and valve operation accurately.
• Flange type side connecting pipe is assembled in factory before shipment.
1 For brazing to the connecting pipe with flange, remove the connecting pipe
with flange from the ball valve, and braze it outside of the unit.
2 During the time when removing the connecting pipe with flange, remove
the seal attached on the rear side of this sheet and paste it onto the flange
surface of the ball valve to prevent the entry of dust into the valve.
3 The refrigerant circuit is closed with a round, close-packed packing upon
shipment to prevent gas leak between flanges. As no operation can be
done under this state, be sure to replace the packing with the hollow pack-
ing attached at the piping connection.
4 At the mounting of the hollow packing, wipe off dust attached on the flange
sheet surface and the packing. Coat refrigerating machine oil (Ester oil,
ether oil or alkylbenzene [small amount]) onto both surfaces of the pack-
ing.
[Fig. 9.2.1] (P.4)
A Close-packed packing
B Hollow packing
• After evacuation and refrigerant charge, ensure that the handle is fully open. If
operating with the valve closed, abnormal pressure will be imparted to the
high- or low-pressure side of the refrigerant circuit, giving damage to the com-
pressor, four-way valve, etc.
• Determine the amount of additional refrigerant charge by using the formula,
and charge refrigerant additionally through the service port after completing
piping connection work.
• After completing work, tighten the service port and cap securely not to gener-
ate gas leak.
• Flare machining dimension for systems using R410A is larger than that for
systems using other types of refrigerant in order to increase the air tightness.
• Refer to the table on the below for flare machining dimensions, and follow the
regulations set forth by the local authorities. Seal off the opening of the pipe
with a closure material (not supplied) to keep small animals from entering the
pipe if that is a concern.
flare machining dimension (mm)
flare nut size (mm)
α 1
1.0 kg
1.5 kg
2.0 kg
2.5 kg
3.0 kg
4.0 kg
5.0 kg
[Fig. 9.2.2] (P.4)
<A> [Ball valve (Low press. side/flanged type)]
α 2
<B> [Ball valve (High press. side/flanged type)]
0 kg
<C> This figure shows the valve in the fully open state.
1.0 kg
A Valve stem
2.0 kg
α 3
B Stopper pin [Prevents the valve stem from turning 90° or more.]
0 kg
C Packing (Accessory)
2.0 kg
D Connecting pipe (Accessory)
E Open (Operate slowly)
F Cap, copper packing
G Service port
H ø22.2 (PQRY-P400)
I ø28.58 (PQRY-P400)
J Field piping
[Fig. 9.2.3] (P.4)
A Heat exchanger unit
B Compressor unit
C Low press pipe (BC controller side ø28.58)
D High press pipe (BC controller side ø22.2)
E Heat exchanger unit – Compressor unit connection pipe (ø28.58 Flange + Brazed)
F Heat exchanger unit – Compressor unit connection pipe (ø19.05 Flare + Brazed)
G Heat exchanger unit – Compressor unit connection pipe (ø9.52 Flare + Brazed)
H Ball valve
I External heater adapter (3-wire)
• Connect the pipes on the compressor unit and heat exchanger unit on site.
Pipe sizes are shown below.
Perform piping work according to the instructions in section 9.4 Thermal insu-
lation of refrigerant piping.
Appropriate tightening torque by torque wrench:
Copper pipe external dia. (mm)
Tightening angle standard:
Pipe diameter (mm)
ø6.35, ø9.52
ø12.7, ø15.88
ø19.05
outer diameter size in inches
ø6.35 1/4"
ø9.52 3/8"
ø12.70 1/2"
ø15.88 5/8"
ø19.05 3/4"
outer diameter size in inches
ø6.35 1/4"
ø9.52 3/8"
ø12.70 1/2"
B
ø15.88 5/8"
ø19.05 3/4"
[Fully closed at the factory, when connecting the piping, when evacuating, and
when charging additional refrigerant. Open fully after the operations above are
completed.]
[Manufacturer: Nichiasu corporation]
[Type: T/#1991-NF]
[Use packing and securely install this pipe to the valve flange so that gas leakage
will not occur. (Tightening torque:40 N·m) Coat both surfaces of the packing with
refrigerating machine oil. (Ester oil, ether oil or alkylbenzene [small amount])]
[Remove the cap and operate the valve stem. Always reinstall the cap after op-
eration is completed. (Valve stem cap tightening torque: 23 ~ 27 N·m)]
[Use this port to evacuate the refrigerant piping and add an additional charge at
the site.
Open and close the port using a double-ended wrench.
Always reinstall the cap after operation is completed. (Service port cap tightening
torque: 12 ~ 15 N·m)]
ø22.2 (PQRY-P500)
ø28.58 (PQRY-P500)
ø6.35
ø9.52
ø12.7
ø15.88
ø19.05
Tightening angle (°)
60 to 90
30 to 60
20 to 35
dimension A
R410A
9.1
13.2
16.6
19.7
24.0
dimension B
R410A
17.0
22.0
26.0
29.0
36.0
Tightening torque (N·m)
14 to 18
35 to 42
50 to 57.5
75 to 80
100 to 140
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