Mitsubishi Electric CITY MULTI PUHY-P-YKB-A1 Manuel D'installation page 21

・If the length of the pipe between the branching point and the outdoor unit exceeds 2 m (6 ft), provide a trap within 2
m (6 ft) from the branching point.
The trap must be at least 200 mm (7-7/8 in) in height. (gas pipe only) If there is no trap, oil can accumulate inside
the pipe, causing a shortage of oil and may damage the compressor.
* Small dots in the figures indicate branching points.
2 m (6 ft)
To indoor units
Ⓐ
Trap (gas pipe only)
Ⓑ
Gas pipe
Ⓒ
9-2. Pipe selection
Use refrigerant piping made of phosphorus deoxidized copper (copper and copper alloy
seamless pipes) that meets local requirements. Pipe joints should also meet local
requirements. Keep the inner and outer surfaces of the pipes clean and free of sulphur,
oxides, dust/dirt, shaving particles, oils, moisture, or any other contaminants.
- Contaminants on the inside of the refrigerant piping will cause the refrigerant oil to deteriorate
and cause the compressor to malfunction.
Use refrigerant pipes for use with R410A refrigerant system. Piping for systems for use with other types of refrigerants
may not be able to be used.
Use refrigerant pipes with the thicknesses specified in the table below.
Size [mm (in)] Radial thickness [mm (mil)]
ø6.35 (ø1/4)
ø9.52 (ø3/8)
ø12.7 (ø1/2)
ø15.88 (ø5/8)
ø19.05 (ø3/4)
ø22.2 (ø7/8)
ø25.4 (ø1)
ø28.58 (ø1-1/8)
ø31.75 (ø1-1/4)
ø34.93 (ø1-3/8)
ø41.28 (ø1-5/8)
KD79S703H01
Ⓐ
Type
0.8 (32) Type-O
0.8 (32) Type-O
0.8 (32) Type-O
1.0 (40) Type-O
1.2 (48) Type-O
1.0 (40) Type-1/2H or H
1.0 (40) Type-1/2H or H
1.0 (40) Type-1/2H or H
1.0 (40) Type-1/2H or H
1.1 (44) Type-1/2H or H
1.2 (48) Type-1/2H or H
1.4 (56) Type-1/2H or H
Ⓑ
Ⓐ
Ⓒ
≤ 2 m (6 ft)
GB-19