Limitation Of Installation And Ahu - Hitachi DXF-2.0A1 Operation Installation Maintenance Manual

2.4

Limitation of Installation and AHU

Limitation of Installation and Application
Refer to Fig. 2.1 "System Overview (1)" and Fig. 2.2 "System Overview (2)" for the following symbols.
L1: the distance* between the heat exchanger of AHU and the Expansion Valve for the piping length
1
H1: the height difference*
L2: the length* of thermistor for Outlet Air/Inlet Air/Liquid Pipe/Gas Pipe
3
L3: the length* of control wires for electrical expansion valve
4
Ti: the suction air temperature*
W2: the total AHU capacity with DX-Kit to outdoor unit capacity*
W1: the total standard indoor unit capacity to outdoor unit capacity*
* The distance must be 5m or less.
1
* The difference must be 2m or less.
2
* The length must be 10m or less.
3
* The length must be 10m or less.
4
5
* The temperature range must be:
Cooling: 21°CDB/15°CWB ~ 32°CDB/23°CWB
Heating: 15°CDB ~ 27°CDB
* The capacity for Multi combination with AHU and standard indoor unit must be:
6
< W1+W2: More than 100 to 110% >
W2: maximum 30%
Allowable AHU capacity in a system: 2 to 6HP
< W1+W2: 50 to 100% >
W2: No Limitation
Allowable AHU capacity in a system: No Limitation
Minimum indoor unit capacity or AHU capacity:
Max. Capacity of Single AHU in
system
12 to 20 HP
22 to 30 HP
32 to 60 HP
62 to 90 HP
For Single combination with only AHU:
W2: maximum 50 to 100%.
P5417151-rev.1
between the heat exchanger of AHU and the Expansion Valve
2
just before the DX-coil.
5
Min. indoor unit capacity or
Min. AHU capacity in a system
6
6
0.8 HP
2.0 HP
4.0 HP
6.0 HP
9