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Light Sensor, FM

Light Sensor, FM

Product code: 2CDG110089R0011
The light sensor is used to measure the brightness level in rooms. When combined with the light controller LR/S, DLR/S, DLR/A and LR/M1.6.2 the light sensor is used for constant light control.
Price (Excluding VAT)


The ABB KNX light sensor LF/U 2.1 is a brightness sensor for closed rooms.
The light sensor is mounted in a standard installation box in the ceiling.

The cover (white) of the sensor is stuck firmly onto the device. The complete unit is then screwed into a flush-type box.

On the Light Controller LR/S x.16.1 (x = 2 or 4) up to 2 or 4 Light Sensors LF/U 2.1 can be connected. The light sensor measures brightness values in closed rooms. When combined with the detected values, the Light Controller is used for constant light control. It is possible to combine the brightness values from several Light Sensors for the calculation of an individual control circuit.

It is thus possible to achieve control of the lighting in rooms with difficult lighting conditions.

The electrical connection to the Light Sensor on the Light Controller is carried out with a twin core MSR cable (SELV), e.g. KNX bus cable. The total length of this cable may not exceed 100 m. The Light Sensor is supplied with a Plexiglas rod which snaps into the sensor housing. The detection range can be limited  using the Plexiglas rod with the white coating. The Light Controller and the connect Light Sensor are supplied with power via the KNX and do not require any additional power supply.

Technical Details


  • Operating Voltage: Powered by LR/S, DLR/S, DLR/A or LR/M1.6.2
  • Brightness measuring range: 200-3000 LUX Depending on reflection value of furnishings- Optimised for 500 LUX
  • Optimum installation Height: 2-3m
  • Max. cable cross section: 2.5 mm2
  • Cable length: 100 m using .8mm KNX Cable



Technology KNX
Brand ABB
Colour/Material White
Frame finish White
Mounting Flat
IP rating IP20
EAN 40 16779 66416

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