Refrigerant Pipe And Drain Pipe Specifications; Refrigerant Pipe, Drain Pipe And Filling Port; Request For Refrigerant Piping Connection; Connecting Refrigerant Pipes And Drain Pipes - Mitsubishi Electric CITY MULTI PEFY-P-VMH-E-F Série Manuel D'installation

6. Refrigerant pipe and drain pipe specifications

To avoid dew drops, provide sufficient antisweating and insulating work to the re-
frigerant and drain pipes.
When using commercially available refrigerant pipes, be sure to wind commer-
cially available insulating material (with a heat-resisting temperature of more than
100 °C and thickness given below) onto both liquid and gas pipes.
Be also sure to wind commercially available insulating material (with a form
polyethylene's specific gravity of 0.03 and thickness given below) onto all pipes
which pass through rooms.
6.1. Refrigerant pipe and drain pipe specifications
[Fig. 6.1.1] (P. 3)
A Flare cutting dimensions
C Apply refrigerating machine oil over the entire flare seat surface
A Flare cutting dimensions
Copper pipe O.D. (mm)
B Refrigerant pipe sizes & Flare nut tightening torque
Liquid pipe
Tightening
Pipe size
P80 O.D.ø9.52 (3/8") 34 – 42
P140 O.D.ø9.52 (3/8") 34 – 42
* Use the provided flare nut for the following pipes: Liquid pipe of P140.
6.2. Refrigerant pipe, drain pipe and filling
port
[Fig. 6.2.1] (P. 3)
A Air inlet
C Refrigerant piping (gas)
E Drain outlet
6.3. Request for refrigerant piping connec-
tion
Connecting refrigerant piping
• After connecting refrigerant piping, insulate the joints (flared joints) with ther-
mal insulation tubing as shown below.
[Fig. 6.3.1] (P. 3)
A Thermal insulation tubing 1
B Caution:
Pull out the thermal insulation on the refrigerant piping at the site, insert the flare
nut to flare the end, and replace the insulation in its original position.
Take care to ensure that condensation does not form on exposed copper piping.

7. Connecting refrigerant pipes and drain pipes

7.1. Refrigerant piping work

This piping work must be done in accordance with the installation manuals for both
outdoor unit and BC controller (simultaneous cooling and heating series R2).
• Series R2 is designed to operate in a system that the refrigerant pipe from an
outdoor unit is received by BC controller and branches at the BC controller to
connect between indoor units.
• For constraints on pipe length and allowable difference of elevation, refer to
the outdoor unit manual.
• The method of pipe connection is flare connection.
Cautions On Refrigerant Piping
s s s s s Be sure to use non-oxidative brazing for brazing to ensure that no for-
eign matter or moisture enter into the pipe.
s s s s s Be sure to apply refrigerating machine oil over the flare connection seat-
ing surface and tighten the connection using a double spanner.
s s s s s Provide a metal brace to support the refrigerant pipe so that no load is
imparted to the indoor unit end pipe. This metal brace should be pro-
vided 50 cm away from the indoor unit's flare connection.
8
B Refrigerant pipe sizes & Flare nut tightening torque
ø9.52
ø15.88
ø19.05
R410A
Gas pipe
Tightening
torque Pipe size torque
(N·m) (N·m)
O.D.ø15.88 (5/8") 68 – 82
O.D.ø15.88 (5/8") 100 – 120
B Refrigerant piping (liquid)
D Control box
F Air outlet
1 Select the thickness of insulating material by pipe size.
Pipe size
6.4 mm to 25.4 mm
28.58 mm to 38.1 mm
2 If the unit is used on the highest story of a building and under conditions of
high temperature and humidity, it is necessary to use pipe size and insulating
material's thickness more than those given in the table above.
3 If there are customer's specifications, simply follow them.
Flare dimensions øA dimensions (mm)
R407C or R22
Liquid pipe
Tightening
Pipe size torque Pipe size
(N·m)
O.D.ø9.52 (3/8") 34 – 42 O.D.ø15.88 (5/8")
O.D.ø9.52 (3/8") 34 – 42 O.D.ø19.05 (3/4")
C Liquid end of refrigerant piping
E Site refrigerant piping
G Marked "GAS"
I Flared insulation (supplied) 2
K Thermal insulation
M Flare nut
O Ensure that there is no gap here
Q Outside
S Remove tape
T Thermal insulation tubing (small) (supplied) 1
U Tie (large) (supplied) 4
V Ensure that there is no gap here. Place join upwards.
Refrigerant amount adjustment
Refer to the installation manual for the outdoor unit for details on adjusting the
amount of refrigerant.
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 refrigerant piping made of C1220 (Cu-DHP) phosphorus deoxidized
copper as specified in the JIS H3300 "Copper and copper alloy seamless
pipes and tubes". In addition, be sure that the inner and outer surfaces of
the pipes are clean and free of hazardous sulphur, oxides, dust/dirt, shav-
ing particles, oils, moisture, or any other contaminant.
• Never use existing refrigerant piping.
- 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.
• Use Suniso 4GS or 3GS (small amount) refrigerator oil to coat the flare
and flange connection part. (For models using R22)
Insulating material's thickness
More than 10 mm
More than 15 mm
12.8 – 13.2
19.3 – 19.7
22.9 – 23.3
Flare nut O.D.
Gas pipe
Tightening Liquid
torque pipe
(N·m) (mm)
68 – 82 22
100 – 120* 22
D Gas end of refrigerant piping
F Main body
H Marked "OUTSIDE"
J Marked "INSIDE"
L Pull
N Return to original position
P Plate on main body
R Inside
Gas
pipe
(mm)
29
36