18
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Piping installation
Installer and user reference guide
79
RXYLQ10~14T7Y1B*
VRV IV system air conditioner
4P543427-1A – 2020.10
6,7
VRV DX indoor units
Maximum allowable length
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Between outdoor unit and indoor unit.
Actual piping length
100 m
Example:
a+b+g+l≤100 m
Equivalent length
(a)
120 m
Total piping length
250 m
Example:
a+b+d+g+l+k+c+e+f+h+i+j≤250 m
(a)
Assume equivalent piping length of refnet joint=0.5 m and refnet header=1 m (for
calculation purposes of equivalent piping length, not for refrigerant charge calculations).
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Between BP unit and indoor unit.
Indoor unit capacity index
Pipe length
<60
2~15 m
60
2~12 m
71
2~8 m
Remark:
Minimum allowable length
between outdoor unit and first refrigerant
branch kit>5 m (the refrigerant noise from the outdoor unit can be transmitted).
Example: a>5 m
Maximum allowable height difference
H1
≤50 m (40 m) (if outdoor is located below indoor units)
H2
≤15 m
H4
≤40 m
H5
≤15 m
H6
≤5 m
Maximum allowable length after branch
The pipe length from the first refrigerant branch kit to the indoor unit ≤50 m.
Example: b+g+l≤50 m
If the piping length between the first branch and BP unit or VRV DX indoor unit is
over 20 m, it is necessary to increase the gas and liquid piping size between the
first branch and BP unit or VRV DX indoor unit. If the piping diameter of the sized
up piping exceeds the diameter of the piping before the first branch kit, than the
latter also requires a liquid piping and gas piping size up.
18.1.9 Multiple outdoor units: Possible layouts
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The piping between the outdoor units must be routed level or slightly upward to
avoid the risk of oil retention into the piping.
