Trane CXAJ series Installation, Operation And Maintenance Manual page 49

Building Control System
Host computer
RS458 communication
wire (Modbus)
Up to 15 Modbus modules
See Operation Manual for CXAJ Series Modbus Module for the specific wiring and operation of
Modbus module.
Control of electrical heater (installed by the user as required)
In the heating mode of the unit, when the water return temperature is lower than the set value 5
℃ ( for the single-compressor unit) or the water return temperature is lower than or equal to the
set value 6 ℃ (for the double-compressor unit), start the electrical heater; when the water return
temperature is higher than or equal to the set value minus 2 ℃ , turn off the electrical heater.
Modbus module
Modbus module
Modbus module
Up to 25pcs
RS458 communication wire
Up to 25pcs
RS458 communication wire
Up to 25pcs
RS458 communication wire
Centralized
controller
Centralized
controller
Centralized
controller
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