Installation; Physical Connection; Power Supply; Modbus Connections - Procon A1M Installation Manual

7. Installation

7.1. Physical connection

The MelcoBEMS MINI (A1M) has a 1 metre flying lead to connect directly into the CN105/CN92 connector on the
controller PCB. As an example, Figure 2 shows this connection on a Mr Slim indoor unit and a CRHV unit.

7.2. Power supply

The MelcoBEMS MINI (A1M) is powered from the CN105/CN92 air conditioner host connector at 12V DC and therefore
does not require an external power supply.

7.3. Modbus connections

The MelcoBEMS MINI (A1M) has a 3-way screw terminal to provide Modbus RTU communication via RS-485. Figure 1
shows the RS-485 connections. The Modbus section contains further detail of the Modbus communications.

7.4. Unit type selection

The MelcoBEMS MINI (A1M) software will automatically detect whether an Air-To-Air or Air-To-Water unit is connected.
It will then only send commands applicable to that unit type.
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