Mitsubishi Electric City Multi PQHY-P-YSHM-A-BS Manuel D'installation page 7

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[Fig. 9.2.3]
<A> When the piping on the heat source unit side (from the twinning
pipe) exceeds 2 m, ensure a trap (gas pipe only) within 2 m. Make
sure the height of the trap is 200 mm or more.
If there is no trap, oil can accumulate inside the pipe, causing a
shortage of oil and may damage the compressor.
(for PQHY-P·YSHM-A)
<B> Pipe connection example (for PQHY-P·Y(S)HM-A)
E
A : Indoor unit
B : Trap (gas pipe only)
C : Within 2 m
D : Twinning pipe
E : Pipes on site
F : Twinning kit
G : Straight run of pipe that is 500 mm or more
D
A
2m
B
D
A
C
F
G E
9.2
[Fig. 9.2.4]
A
<A> The piping from the heat source units to twinning pipe must be made to
slope downwards the twinning pipe. (both the liquid and the gas side for
PQHY-P·YSHM-A, the high-pressure side only for PQRY-P·YSHM-A)
<B> Slope of twinning pipes (for PQHY-P·YSHM-A)
Make sure the slope of the twinning pipes are at an angle within ±15° to the
horizontal plane.
If the slope exceeds the specifi ed angle, the unit may be damaged.
E
<C> Pipe connection example (for PQRY-P·YSHM-A)
H
A : Downward slope
B : Upward slope
C : BC controller (standard or main)
D : Twinning pipe
E : Slope of the twinning pipe is at an angle within ±15° to the ground
F : Twinning pipe (low-pressure side)
G : Twinning pipe (high-pressure side)
H : On-site piping (low-pressure connecting pipe: between heat source units)
I : On-site piping (low-pressure main pipe: to BC controller)
J : On-site piping (high-pressure main pipe: to BC controller)
C
D
C
B
D
D
F
I
G
J
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