Rheem W2W Series Owner's Manual And Installation Instructions page 47

CONNECTIONS - ELECTRICAL
Building Management Systems (BMS/BAS)
Each water heater can be connected to a BMS or BAS system via interface cards
(Modbus or BACnet), available as an accessory.
Based on site requirement, a suitable interface card needs to be connected to
Rheem IQ control panel as shown in the diagram below.

If the system is comprised of single or multiple standalone heat pumps, each
heat pump will have its own BMS card.
Insert the BMS card into the connector for each heat pump, taking care that the
card is firmly placed as shown in red circle.

If the system is comprised of multiple heat pumps for Master/Slave operation,
only master heat pump will have a BMS card and the slave heat pumps will
be connected via LAN cables.
Follow the instruction on page 45 for Interconnecting Multiple Heat Pumps from
step 1 to step 2.
Insert the BMS card into the connector for Master heat pump, taking care that
the card is firmly placed as shown in red circle.
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