The ABB UD/S4.210.2.1 KNX LED Dim Actuator is a multichannel universal dimming actuator optimised for retrofit LED lamps (LEDi) in ABB i-bus® KNX projects. Four independent channels deliver up to 4 × 210 W/VA at 230 V~, with outputs combinable in parallel for a maximum of 1 × 600 W/VA on a single load.

Install on standard 35 mm DIN rail (MDRC). The module includes an integrated KNX bus coupler and supports commissioning with or without applied mains voltage — a practical advantage during early project phases.

Key Features and Dimming Capabilities

The UD/S4.210.2.1 is engineered for stable dimming across modern LED retrofits and legacy lamp types, with per-channel neutral wiring for flexible circuit design.

Universal Load Support

• 4 dimming channels: Independent control of four lighting circuits with separate N-connection per channel.
• LEDi optimised: Dimmable 230 V~ LEDi up to 4 × 210 W/VA (trailing edge) or 4 × 80 W/VA (leading edge); parallel up to 1 × 600 W/VA / 1 × 200 W/VA respectively.
• Legacy compatibility: Incandescent, 230 V halogen, low-voltage halogen (conventional L or electronic C transformers), and dimmable energy-saving lamps.
• Transformer loads: Inductive L-transformers and electronic C/LC-transformers with LED or LV halogen — see Technical Specifications for per-type limits.
• Minimum load: 2 W for stable dimming of low-power LED circuits.

Commissioning, Diagnostics, and Control

• Automatic load detection: Identifies connected load type automatically (can be deactivated).
• Parallel outputs: Channels can be connected in parallel in any configuration to increase output power.
• Manual operation: On-device control possible without bus voltage or in unprogrammed status.
• Safe programming: Device can be configured without applied 230 V supply voltage.
• ABB i-bus® Tool: Extensive test and diagnosis functions for field troubleshooting.
• ETS efficiency: Fast parameterisation using copyable channel templates.

At a Glance

Specification	Detail
Product type	Universal LED dimming actuator, 4-fold
Order code	UD/S4.210.2.1 (2CKA006197A0047)
Channels	4 independent dimming outputs
Nominal power (230 V~ LEDi, trailing edge)	4 × 210 W/VA → 1 × 600 W/VA parallel
Minimum load	2 W
Input voltage	110 … 230 V AC/DC, 50/60 Hz
Mounting	DIN rail MDRC, 6M (105 mm wide)
Protection	IP20
Bus system	KNX twisted pair (TP)

Full load-type ratings, dimensional data, and classification codes — including ETIM EC001094 and EAN 4011395251867 — are listed under Technical Specifications.

Applications and KNX Integration

• LED retrofit projects: Stable trailing-edge dimming for modern 230 V~ LEDi in offices, hotels, and residential schemes.
• Mixed lamp types: One actuator covers incandescent, halogen, and LED loads in renovation projects without replacing all luminaires at once.
• High-power zones: Parallel channel connection for large dining rooms, lobbies, or open-plan areas up to 600 W/VA.
• ETS configuration: Import the official .knxprod application (Downloads), assign group addresses, scenes, and daylight-linked control from KNX sensors and touch panels.
• Project documentation: Data sheet, product manual, connection diagrams, dimensional drawing, CAD, and EPLAN data are available under Downloads.

Choosing UD/S Universal Dim Actuators

ABB offers the UD/S family in several channel counts and power ratings. The UD/S4.210.2.1 (4 × 210 W/VA) suits standard multi-circuit lighting panels. For higher per-channel headroom, consider UD/S4.315.2.1 (2 × 315 W/VA) or UD/S6.210.2.1 (6 × 210 W/VA) when six independent dimming circuits are required in one MDRC position.