System Control Unit SCU 2421 / SCU 2442

The system control unit is the brain of an electrically actuated suppression or flooding system: it monitors the detection zones, runs the evacuation countdown, drives the alarms and commands release.

Supplied as the SCU 2421 with 2 zones and 1 solenoid output, or the SCU 2442 with 4 zones and 2 solenoid outputs - so one panel can protect a single room or two independent risks. Three NAC outputs drive sounders and beacons, and the solenoid output supplies 24 V at 0.75 A to the release actuator. A dedicated fire relay (C, NO, NC) plus two programmable relays let the panel interlock with plant shutdown, dampers, gas shut-off valves and building management systems.

Housed in a powder coated mild steel box, mains supplied at 220 V AC with 24 V DC operation and battery backup, rated 0 to 50 °C.

Configuration review. Catalogue reference data for System Control Unit SCU 2421 / SCU 2442: Construction: Powder Coated Mild Steel Box; Power Supply: 220 V AC; Operating Nominal Voltage: 24 V DC. These values describe this product. Confirm the remaining interfaces and operating requirements against the system drawing and current manufacturer documentation.

Selection checks. Confirm the required cause-and-effect sequence and distinguish supervisory duties from electrical release control. Check every input and output type against the connected devices, including supervision, load and backup arrangements. Include the building interfaces and the agreed commissioning sequence with the enquiry.

Before ordering. For a System Control Unit SCU 2421 / SCU 2442 quotation, provide the required quantity, installation or replacement context, and the associated equipment model. Include photographs or drawings of the interfaces and any project documentation requirements. Ask the supplier to identify the exact offered configuration and the scope of installation, commissioning or servicing included.