User Guide | Optyma™ iCO2
14 | BC408445719305en-000101
© Danfoss | Climate Solutions | 2023.01 | LCA012A030
2. Module controller
2.1 System Overview
Below is a topology over the system
System Manager
Condensing unit
AK-SM 800/800A
AK-CC55
Remote control assembly
Evaporator controllers
User interface
12VDC
Power Supply
12VDC
+12VDC
230VAC
Modbus RTU
Modbus RTU
230VAC
Modbus RTU
CO2 MODULE CONTROLLER
UNIVERSAL GATEWAY
INPUT 12 VDC
RS485-1
GND
A -
B -
GND
A -
B -
RS485-2
GND
A -
B -
-
+
RS485-3
PWR
RJ12
Module controller
assembly
Functions
• Control of connected condensing unit (CDU).
• Coordination of oil recovery.
• Communication with a Danfoss System Manager.
Condensing unit
The connected condensing unit is allowed to start when any of the evaporator controllers have a cooling demand.
Oil recovery
The controller coordinates oil recovery operation between the condensing unit and the evaporator controllers. During oil recovery the
expansion valves are opened and the speed of the compressor is increased.
Data communication
The controller is delivered with three interfaces for Modbus communication, each with their own function:
1. Communication with System Manager
This interface lets a Danfoss System Manager find both the connected condensing unit and all the connected evaporator controllers.
2. Communication with condensing unit
3. Communication with evaporator controllers
Important
All connections to the data communication must comply with the requirements for data communication cables.
See literature: Design guide RC8AC Data communication between ADAP-KOOL® Refrigeration Controls.
Note:
No direct possible link between System Manager and unit controller, you need to connect to Module controller