Fujitsu AJ*A72LALH Series Installation Manual page 28

(3) Number o f outdoor units installed
The number of outdoor units installed in 1 refrigerant system must be set.
Set for all outdoor units.
SET5
Number of out-
1 2
OFF OFF
OFF ON
ON OFF
ON ON
7. 2. 3. Terminating resistor setting
Be sure to set the terminal resistor according to specifi cations.
Set the terminal resistor for every network segment (NS).
If terminal resistor is set in multiple devices, the overall communication system may be damaged.
If terminal resistor is not set in a device, abnormal communication may occur.
• Be sure to set 1 terminal resistor in a network segment. You can set the terminal resistor at the outdoor unit or
signal amplifi er.
• When settin g the terminal resistor of a signal amplifi er, refer to the installation manual of the signal amplifi er.
• When settin g multiple terminal resistors, take note of the following items.
How many network segments are there in a VRF system?
Where will you set the terminal resistors in a network segment? (Condition for 1 segment: Total number of
outdoor and indoor units and signal amplifi ers is less than 64, or the total length of the transmission cable is
less than 500m)
How many outdoor units are connected to 1 refrigerant system?
Confi gure the setting (DIP switch SET5) of the terminal resistor of the outdoor units as shown below from con-
ditions 1 to 3.
SET5
Terminal resistor
4
OFF
ON
Master unit
Master unit
Master unit
NS2 (Network segment 2)
En-28
door units
1 (Factory setting)
2
3
-
Disable (Factory setting)
Enable
NS1 (Network segment 1)
(Set terminal resistor at outdoor units)
Terminal resistor: on
Refrigerant system1
Terminal resistor: off
Refrigerant system2
Refrigerant system3
NS3 (Network segment 3)
Terminal resister: on
Remarks
-
-
Forbidden
Caution
Remarks
-
About the setting of terminal resistor
NS4 (Network segment 4)
Outdoor unit (Master unit)
:on
:off
Signal amplifi er
Install
Do not install