Refrigerant Pipe And Drain Pipe Specifications; Refrigerant Pipe, Drain Pipe And Filling Port; Connecting Refrigerant Pipes And Drain Pipes; Refrigerant Piping Work - Mitsubishi Electric PWFY-P100VM-E-BU Installation Manual

8. 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
1 Select the thickness of insulating material by pipe size.
Model
Gas
Liquid
Drain
Insulating material's thickness
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.

8.1. Refrigerant pipe, drain pipe and filling port

[Fig. 8.1.1] (P. 3)
A Refrigerant piping (gas)
C Water inlet
E Drain outlet

9. Connecting refrigerant pipes and drain pipes

9.1. 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 brazing connection.
Caution:
• Install the refrigerant piping for the indoor unit in accordance with the
following.
1. Cut the tip of the indoor unit piping, remove the gas, and then remove the
brazed cap.
[Fig. 9.1.1] (P.3)
A Cut here
B Remove brazed cap
2. Pull out the thermal insulation on the site refrigerant piping, braze the unit
piping, and replace the insulation in its original position.
Wrap the piping with insulating tape.
Note:
• Pay strict attention when wrapping the copper piping since wrapping the
piping may cause condensation instead of preventing it.
* Before brazing the refrigerant piping, always wrap the piping on the main
body, and the thermal insulation piping, with damp cloths to prevent heat
shrinkage and burning the thermal insulation tubing. Take care to ensure
that the flame does not come into contact with the main body itself.
[Fig. 9.1.2] (P.3)
A Thermal insulation
C Wrap with damp cloth
E Ensure that there is no gap here
PWFY-P100VM-E-BU
ø15.88
ø9.52
B Refrigerant piping (liquid)
D Water outlet
*1: PWFY-P100/200VM-E-AU
B Pull out insulation
D Return to original position
F Wrap with insulating tape
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.
PWFY-P100VM-E-AU
ø15.88
ø9.52
ø32
More than 10 mm
3 If there are customer's specifications, simply follow them.
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.
Warning:
When installing and moving the unit, do not charge it with refrigerant other
than the refrigerant (R407C or R22) 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,
shaving 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.
PWFY-P200VM-E-AU
ø19.05
ø9.52
9