3SK1111-1AB30 SIRIUS 3SK1 Standard Safety Relay 3NO/1NC 24V AC/DC | Siemens

The Original New Siemens 3SK1111-1AB30 SIRIUS 3SK1 Standard Safety Relay Basic Unit is a compact, high‑reliability control device designed for autonomous safety applications in industrial automation systems. Featuring 3 positively‑driven relay enabling circuits (NO contacts) and 1 signaling circuit (NC contact), it provides a cost‑effective solution for machine safety functions. This device is configured as a two‑channel safety relay for EMERGENCY OFF and EMERGENCY STOP equipment in accordance with EN 60204‑1. It offers single‑channel or two‑channel sensor inputs, cross‑circuit detection, and self‑monitoring during every ON/OFF cycle. Configurable via a front‑facing slide switch, the 3SK1111-1AB30 is ideally suited for safety functions with a few sensors and enabling circuits, replacing the proven 3TK28 series.

Core Engineering Highlights:
SIL 3 (IEC 61508) | PL e (ISO 13849‑1) | Category 4 (ISO 13849‑1) | 3 safety relay outputs (NO) + 1 signaling output (NC) | 24V AC/DC supply voltage | 5A contact rating | 2 sensor inputs | Cross‑circuit detection | Positively‑driven relays | Self‑monitoring | Screw terminals | IP20 | –25°C to +60°C operating temperature | 22.5mm width

Key Features:

• Original New Siemens 3SK1111-1AB30 safety relay

• 3 positively‑driven safety relay outputs (NO contacts) for enabling circuits

• 1 signaling circuit (NC contact) for status indication

• SIL 3 (IEC 61508) and PL e (EN ISO 13849‑1), Category 4 certified

• 2 sensor inputs for single‑channel or two‑channel connection

• Cross‑circuit detection between sensor channels 1 and 2

• Positively‑driven relays with self‑monitoring during every ON/OFF cycle

• 1 input for feedback circuit and START button

• Slide switch for function setting on the front of the device

• 2 LEDs for clear display of operating states

• 24V AC/DC supply voltage with wide operating range

• Screw‑type terminal connection for secure and reliable wiring

• Narrow 22.5mm housing for space‑saving control cabinet installation

• Simple, variable functionality — an economical entry into safety relay applications

• Replaces the proven 3TK28 series

• Suitable for monitoring emergency‑stop circuits, magnetic switches, position switches, and optoelectronic protection equipment

Applications:

• EMERGENCY OFF and EMERGENCY STOP monitoring per EN 60204‑1

• Safety gate and protective door monitoring

• Light curtain and optoelectronic protection equipment integration

• Two‑hand control systems

• Machine safety circuits requiring up to SIL 3 / PL e / Category 4

• Standalone safety applications with a few sensors and enabling circuits

Technical Specifications:

System Compatibility:

• Siemens SIRIUS 3SK1 safety relay system architecture

• Compatible with mechanical and electronic safety sensors

• Emergency stop pushbuttons, safety switches, light curtains, and two‑hand control devices

• 3RQ1 positively‑driven coupling relays

• SIRIUS 3RM1 motor starters (via accessories)

Typical System Architecture:
24V AC/DC Power Supply
↓
3SK1111-1AB30 Safety Relay (DIN rail mount)
│
├── Sensor Inputs (Channel 1 + Channel 2) → Emergency Stop / Safety Switch / Light Curtain
├── Feedback / START Input → Contactor feedback / Start button
│
├── Safety Outputs (3 NO) → Motor contactors / Actuators
└── Signaling Output (1 NC) → PLC input for status monitoring
↓
Front Slide Switch (Configuration: Auto‑start / Monitored start)
↓
2 LEDs (Operating state display)

Related Products:

• 3SK1111-1AW20 – 110‑240V AC/DC wide‑range version

• 3SK1111-2AB30 – 24V AC/DC with spring‑loaded (push‑in) terminals

• 3SK1112-1AB30 – Advanced series with semiconductor outputs

• 3SK1211-1BB00 – Advanced series basic unit, 24V DC, spring terminal

• 3RQ1 – Positively‑driven coupling relays

• Sealing covers, push‑in lugs, and coding pins – Mounting accessories

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