The ABB UD/S4.315.2.1 KNX Universal Dimmer is a high-power multichannel universal dimming actuator optimised for retrofit LED lamps (LEDi) in ABB i-bus® KNX projects. Two independent channels deliver up to 2 × 315 W/VA at 230 V~, with outputs combinable in parallel groups for a maximum of 1 × 500 W/VA on a single load — ideal when fewer circuits need higher per-channel headroom than the 210 W UD/S4.210 family.

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.

Key Features and Dimming Capabilities

The UD/S4.315.2.1 targets projects where individual dimming circuits require up to 315 W/VA while keeping channel count manageable in the distribution board.

High-Power Universal Load Support

• 2 dimming channels: Independent control of two lighting circuits with separate N-connection per channel.
• LEDi optimised: Dimmable 230 V~ LEDi up to 2 × 315 W/VA (trailing edge) or 2 × 120 W/VA (leading edge); parallel grouping up to 1 × 500 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 with LED or LV halogen — up to 2 × 315 W/VA or 1 × 500 W/VA parallel.
• 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 output groups: Channels can be connected in parallel within groups 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, 2-fold × 315 W/VA
Order code	UD/S4.315.2.1 (2CKA006197A0052)
Channels	2 independent dimming outputs
Nominal power (230 V~ LEDi, trailing edge)	2 × 315 W/VA → 1 × 500 W/VA parallel
Minimum load	2 W
Input voltage	110 … 230 V AC/DC, 50/60 Hz
Dimensions (W × H × D)	120 × 95 × 130 mm
Protection	IP20
Bus system	KNX twisted pair (TP)

Full load-type ratings and classification codes — including ETIM EC001094 and EAN 4011395251911 — are listed under Technical Specifications.

Applications and KNX Integration

• High-power LED zones: Conference rooms, restaurant dining areas, and lobbies where a single circuit exceeds 210 W/VA but two 315 W channels suffice.
• Mixed lamp types: Renovation projects combining halogen, incandescent, and LEDi on the same actuator platform.
• Grouped parallel loads: Pair channels for up to 500 W/VA on one controlled output.
• ETS configuration: Import the official .knxprod application (Downloads), assign group addresses, scenes, and daylight-linked control from KNX sensors such as the 6131/20-24-500 Presence Mini W.
• Project documentation: Product manual, connection diagram, dimensional drawing, CAD, and EPLAN data are available under Downloads.

Choosing UD/S Universal Dim Actuators

ABB offers the UD/S family at several power and channel ratings. The UD/S4.315.2.1 (2 × 315 W/VA) suits panels needing higher per-channel headroom. For standard four-circuit panels at 210 W, choose UD/S4.210.2.1. For six independent dimming circuits, choose UD/S6.210.2.1.