13
GB
Precautions for outdoor unit combinations
Refer to [Fig. 9.2.2] for the positioning of twinning pipes.
[Fig. 9.2.2]
<A> Install the piping so that oil will not accumulate in the stopped outdoor unit. (high pressure side only)
1.
D
C
A
Unit 1
Unit 2
D
C
B
Unit 1
Unit 2
The NG example shows that oil accumulates because the units are installed on a reverse gradient while unit 1 is in operation, and unit 2 is stopped.
2.
h1
Unit 1
Unit 2
Unit 1
Unit 2
h1 = 0.2 m (7-7/8 in) max
h1
Unit 1
Unit 2
h1 > 0.2 m (7-7/8 in)
The NG example shows that oil accumulates into unit 1 while unit 2 is in operation, and unit 1 is stopped. Vertical pipe height (h1) should be 0.2 m (7-7/8 in) or below.
3.
h2
Unit 1
Unit 2
h2 = 0.1 m (3-15/16 in) max
h2
Unit 1
Unit 2
h2 > 0.1 m (3-15/16 in)
The NG example shows that oil accumulates into unit 1 while unit 2 is in operation, and unit 1 is stopped. Difference between unit and unit in height (h2) should be 0.1 m (3-15/16 in) or
below.
4.
h2
Unit 1
Unit 2
h2 = 0.1 m (3-15/16 in) max
h2
Unit 1
Unit 2
h2 > 0.1 m (3-15/16 in)
The NG example shows that oil accumulates into unit 2 while unit 1 is in operation, and unit 2 is stopped. Difference between unit and unit in height (h2) should be 0.1 m (3-15/16 in) or
below.
<B> Slope of twinning pipes (high-pressure side only)
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±15°
D
E
A
Downward slope
B
Upward slope
C
BC controller
D
Twinning pipe
E
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Caution:
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If a sight glass is installed, inexperienced technicians that use the glass may overcharge the refrigerant.
