Power unit 16A with RMS current measuring

Key features

  • 16A switching capacity
  • 230V AC at 50Hz
  • Terminal connections mains -
    • Earth x2
    • Neutral (N) x2
    • Live in (LIVE)
    • Load output (LOAD)
  • Standard 2 gang fitment
  • 2mm² to 4mm² Mains & LV terminal capacity
  • Power and active LEDs
  • LV quick connector
  • RJ45 quick connector for connection to PRE2000SR3 slave relay
  • Mains Borne Signalling technology
  • Measures RMS current
  • 5-year warranty


The Prefect Irus PRE2000PU3 power unit provides the PRE2000CU3 with SELV voltage and 16A switching capacity.

The PRE2000PU3 power unit supplies the PRE2000CU3 head unit with the necessary power while adding the capability to switch up to 16A resistive.

The power unit also sends and receives the CU3 data via Mains Borne Signalling (MBS).

The PU3 is a standard 2 gang fitment requiring a 35mm or greater surface or sunken box. The fascia incorporates two flex cable clamps and associated knock-outs for flex connections to heaters, TRV valves or water tank elements.

The PU3 fascia is moulded in PC/ABS making it extremely durable, the material is also UV stable and will not discolour over time. The PU3 includes active and power LEDs for easy identification of status.

Twin earth and neutral terminals along with ample wiring room ease installation and safety. The LV terminal is removable for easy installation and if needed product replacement.

A RJ45 connector is available for a quick non wiring connection to a PRE2000SR3 slave relay unit. The PU3 with the use of a second relay, gives the PU3 and CU3 complete control of a twin element hot water tank or a room with multiple heaters.

The PU3 has the ability to measure RMS current of the connected load giving data on energy usage. This feature also allows the Irus system to identify a fault in a load - for example a failed water tank element or room heater. When Connected to a PRE2000SR3 both loads can be independently recorded allowing for monitoring of twin element hot water tanks.


Product Information


Wiring Diagram - Standard electric heating wiring

Wiring Diagram - Single element hot water tank

Wiring Diagram - Twin element hot water tank

Layout Diagram - Typical electric panel heater

Layout Diagram - Electric heating

Layout Diagram - Electric heating and water heating