CIU 903 is a combined monitoring, control and communication unit designed to work directly with a SQFlex pump. When combined with a CIM 280 GRM module, it enables remote monitoring through Grundfos Go. Moreover, CIU 903 can be connected to a start/stop switch, a level switch or a pulsating water meter. .
CIU 903 is designed to work with all SQFlex up to 2500 W.
The communication between CIU 903 and the pump is ensured through the power supply cable. This is called mains-borne signaling (or power line communication), which does not require extra cables between CIU 903 and
the pump.
Start, stop and reset the pump with the start/stop switch. CIU 903 ensures system monitoring and alarm indication.
The pump operation can be monitored through the following indications:
• water reservoir full (level switch)
• pump running.

CIU 903 indicates the following alarms:
• dry running
• service needed:
- no contact to the pump
- overvoltage
- overtemperature
- overload.