MachineU > China Products > Lights & Lighting > Professional Lighting > LED Sensor Lights
5WG1255-2DB21 KNX Brightness Sensor with Constant Light Controller 5-CH UP 255D21
5WG1255-2DB21 KNX Brightness Sensor with Constant Light Controller 5-CH UP 255D21
5WG1255-2DB21 KNX Brightness Sensor with Constant Light Controller 5-CH UP 255D21
5WG1255-2DB21 KNX Brightness Sensor with Constant Light Controller 5-CH UP 255D21
5WG1255-2DB21 KNX Brightness Sensor with Constant Light Controller 5-CH UP 255D21
5WG1255-2DB21 KNX Brightness Sensor with Constant Light Controller 5-CH UP 255D21
Specifications
Power Supply Mode :
KNX bus power supply (DC 24V)
Certification :
CE RoHS
Color :
Light grey
Model Number :
5WG1255-2DB21
Communication :
KNX bus system
Payment Terms :
T/T,Western Union
Packaging Details :
Carton
Controltype :
Manual and Remote
Delivery Time :
7 Days
Channel Configuration :
16 independent control channels
Place of Origin :
EU
Operating Temperature :
-10°C to 50°C
MOQ :
5
Description
5WG1255-2DB21 KNX Brightness Sensor with Constant Light Controller 5-CH
Product Overview

The 5WG1255-2DB21 (UP 255D21) is a KNX brightness sensor with integrated constant light level controller, designed for ceiling installation. Unlike presence detectors, its primary function is precise illuminance measurement via reflected light from the working plane below, with a range of 0–2,000 lux.

It supports mixed-light measurement to distinguish between daylight and artificial light contributions. The built-in constant light controller manages up to 5 lighting groups (1 main + 4 additional), maintaining a configured lux setpoint by automatically dimming or brightening artificial lighting. An integrated IR receiver supports 6-pair remote control, and the sensor can also detect motion for supplementary occupancy functions.

Technical Specifications
Product Name UP 255D21 – KNX Brightness Sensor with Constant Light Controller
Protocol KNX/EIB Twisted Pair (TP)
Supply Voltage 21–30 V DC via KNX bus (SELV)
Measurement Method Reflected-light measurement from illuminated working plane
Brightness Range 0–2,000 lux (at ~30% surface reflectance)
Monitoring Area 360° horizontal, ~40° vertical; ~2 m diameter measurement zone
Light Source Detection Mixed-light measurement (daylight + artificial light)
Constant Light Control 1 main lighting group + up to 4 additional groups
Control Mode 2-point control, fully automatic or semi-automatic
Sub-group Calibration Auto calibration for up to 4 sub-groups
Auto Disable Constant light control auto-disables on manual dimming
PIR Detection Integrated motion detection (supplementary)
Detection Channels 3 independent output channels + 1 HVAC channel
IR Remote Control Integrated receiver/decoder, 6 button pairs
IR Button Functions Switch, dim, scene recall, value send, shade control
Mounting Ceiling, 60 mm flush-mount box (min. 40 mm depth)
Functional Blocks 3 (Motion, Presence, HVAC)
Bus Coupling Integrated, bus terminal connection
Programming ETS software + front programming button + IR remote
Protection Class IP 20
Certifications CE, KNX certified
ETS Compatibility ETS 4.x and above
Application Scenarios

The UP 255D21 is designed for spaces where maintaining a consistent illuminance level on the working plane is critical, regardless of changing daylight conditions.

Primary applications include offices with large windows, atriums, skylit corridors, retail showrooms, museums, and art galleries — any environment where daylight harvesting must be combined with artificial lighting to maintain visual comfort.

The constant light controller automatically compensates for daylight variations, dimming artificial lights when sufficient natural light is available and increasing output when it is not. The mixed-light measurement ensures accurate distinction between daylight and electric light contributions for precise control.

Send your message to this supplier
Send Now

5WG1255-2DB21 KNX Brightness Sensor with Constant Light Controller 5-CH UP 255D21

Ask Latest Price
Product Detail
Power Supply Mode :
KNX bus power supply (DC 24V)
Certification :
CE RoHS
Color :
Light grey
Model Number :
5WG1255-2DB21
Communication :
KNX bus system
Payment Terms :
T/T,Western Union
Contact Supplier
5WG1255-2DB21 KNX Brightness Sensor with Constant Light Controller 5-CH UP 255D21
5WG1255-2DB21 KNX Brightness Sensor with Constant Light Controller 5-CH UP 255D21
5WG1255-2DB21 KNX Brightness Sensor with Constant Light Controller 5-CH UP 255D21

Maituo Intelligent Technology Co.，Ltd

Verified Supplier
1 Years
hainan, hainan
Since 2015
Business Type :
Manufacturer, Seller, Trading Company, Exporter
Main Products :
Building Controllers, Switch Actuator, Dimming Actuator
Total Annual :
800000 USD-1000000
Employee Number :
50~80
Certification Level :
Verified Supplier
Discover similar products
View More

Find Similar Products By Category:

Supplier Homepage Products Presence Detector
MachineU China Products Lights & Lighting Professional Lighting LED Sensor Lights
Contact Supplier
Submit Requirement