Grundfos CU 200 SQFlex Pump Control Unit The CU 200 control unit is a combined status, controland communication unit developed specifically for theSQFlex system. It enables connection of a level switch, which can turn off the pump when the water reservoir is full. The CU 200 incorporates cable entries for: power supply connection pump connection earth connection level switch connection Communication between the CU 200 and the pump takes place via the pump power supply cable. This is called mains borne signalling (or Power Line Communication), and this principle means that no extra cables between the CU 200 and the pump are required.It is possible to start, stop and reset the pump by meansof the on/off button. The CU 200 control unit offers: System monitoring Alarm indication. The following indications allow the operation of thepump to be monitored: Water reservoir is full (level switch) Pump is running Input power The CU 200 offers the following alarm indications: Dry running Service needed in case of: No contact to pump Overvoltage Overtemperature Overload. In addition, the CU 200 shows the symbols of the energy supply options.