System Design System Design Wy-Series; 1-2.Piping Design - Mitsubishi Electric CITY MULTI Data Book

1. Piping Design
Procedures for installing the branched pipes
Refer to the instructions that came with the branched pipe kit (separately sold) for details.
[1] Branches on the indoor-unit side
■Joint
To outdoor/heat source unit
Horizontal installation
Restrictions for installing the joint described here only apply to CMY-Y202S-G2 and CMY-Y302S-G2 in the gas line.
CMY-Y202S-G2 and CMY-Y302S-G2 in the gas line must be installed horizontally (see figure above) or with the
branched pipes facing up.
If the size of the refrigerant pipe that is selected by following the instructions under "Piping Design" section does not
match the size of the joint, use a reducer to connect them. A reducer is included in the kit.
■Header
To outdoor/heat source unit
No restrictions apply to the installation of the header.
If the size of the refrigerant pipe that is selected by following the instructions under "Piping Design" section does not
match the size of the header, cut the pipe to an appropriate size using a pipe cutter, or use a reducer to connect them.
If the number of header branches exceeds the number of pipes to be connected, cap the unused header branches.
Caps are included in the kit.
[2] Branches on the outdoor/heat source-unit side
Inclination of the twinning pipes
The inclination of the twinning pipes must be ±15° or less against the horizontal plane.
Excessive inclination of the twinning pipes may damage the unit.
Minimum length of the straight section of the pipe before the twinning pipes
Always use the pipes supplied in the twinning pipe kit, and make sure the straight section of the pipe immediately
before it connects to the twinning pipe is at least 500 mm (19-11/16 in.). Failure to do so may damage the unit.
MEES19K187
±15° or less
To indoor unit
Note. Refer to the figure below for the installation position of the twinning pipe.
Twinning pipe
Slope of the twinning pipes are at an angle within ±15° to the horizontal plane.
To branch pipe or indoor unit
Vertical installation
(The branched pipes must face up.)
Indoor-unit side (branched pipe)
±15° or less
Outdoor/heat source-unit side (main pipe)
Pipe cutter
or
Reducer
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