Mitsubishi Electric CITY MULTI PUHY-HP-TNU-A Série Manuel D'installation page 22

・The pipe from multiple outdoor units must be installed so that oil will not accumulate in the pipe under certain
conditions. Refer to the figures below for details.
* Small dots in the figures indicate branching points.
Ⓐ To indoor units
(1) The pipe from the outdoor units must be inclined downward to the indoor unit side. In the figure on the right,
because the pipe is inclined upward, the oil in the pipe accumulates when Unit 1 is in operation and Unit 2 is
stopped.
Unit 1 Unit 2
Ⓐ
(2) The distance between the unit bottom and the pipe (H) must be 0.2 m (7-7/8 in) or below. In the figure on the
right, because the distance is more than 0.2 m (7-7/8 in), the oil accumulates in Unit 1 when Unit 2 is in
operation and Unit 1 is stopped.
Unit 1
Ⓐ
Unit 1
Ⓐ
H
(3) The vertical separation between units (H) must be 0.1 m (3-15/16 in) or below. In the figure on the right,
because the distance is more than 0.1 m (3-15/16 in), the oil accumulates in Unit 1 when Unit 2 is in operation
and Unit 1 is stopped.
Unit 2
Unit 1
Ⓐ
H
(4) The vertical separation between units (H) must be 0.1 m (3-15/16 in) or below. In the figure on the right,
because the distance is more than 0.1 m (3-15/16 in), the oil accumulates in Unit 2 when Unit 1 is in operation
and Unit 2 is stopped.
Unit 1
Ⓐ
・
Unit 2
Unit 2
Unit 2
H
Ⓐ
Unit 1 Unit 2
Ⓐ
Unit 1
Ⓐ
H
H > 0.2 m (7-7/8 in)
Unit 1
Ⓐ
H
Unit 1
Ⓐ
H
Ⓐ
Twinning Kit
Unit 2
Unit 2
H > 0.1 m (3-15/16 in)
Unit 2
H > 0.1 m (3-15/16 in)