Control unit RCBK4/RCBK4-MOD

The RCMU is an encapsulated microprocessor-based, intelligent, self-monitoring control unit.

Quick facts

  • Up to 4 dampers and 4 smoke detectors split into two groups
  • Indicators for each individual damper
  • Optional external incoming alarm
  • Night operation function
  • Alternating relay contacts for both main alarm and dirty detector
  • Alternating relay to, for example, turn off unit during function test
  • Integrated transformer from 230 V to 24 V for powering actuators


The RCMU is an encapsulated microprocessor-based, intelligent, self-monitoring control unit split into two groups, A and B, for connecting up to 2 dampers and 2 detectors in each group. The RCBK4 can act as an independent control unit and perform automatic function tests every 48 hours after power up/resetting. Or it can be connected in a network to a minimaster RCMM for centralised registration, control and monitoring. RCBK4-MOD is used for connection to Modbus. Function tests can also be initiated by an external switch. The control unit has electronic circuits that automatically connect outputs with connected damper actuators.


A microswitch, a so-called DIP switch marked X-conn., is used to set the effect of the detectors as follows:

  • Either detector group A affects damper group A and detector group B affects damper group B (position = 0).
  • Or both damper groups work together regardless of the
    triggering detector group (position = ON).

This enables a single RCBK4 to be used for two independent ventilation systems. The detector outputs feature an electronic short circuit fuse. All connected dampers enter the alarm position in the event of a short circuit or a break in one of the detector loops. The RCBK4 can be set to alarm operation mode by an external incoming alarm.




Room detector


Duct detector