ENG_64194.XML
The 3SF1 position switches with safety-related communication can be directly connected using the AS-Interface bus system. The safety functions no longer have to be wired up conventionally.
With the 3SF1 position switches the ASIsafe electronics are integrated in the switch enclosure.
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Examples of selection options in the modular system
Modular system
The position switches of the 3SF11.4 and 3SF12.4 series are designed as a modular system comprising different versions of the basic switch and an actuator which must be ordered separately. Thanks to the modular design of the switch the end users can select the right solution for their application from numerous versions and install it themselves in a very short time.
Design
The 3SF1 switches are available in four different enclosure sizes:
- Plastic and metal enclosures according to EN 50047, 31 mm wide, with M12 device plug
- Metal enclosures according to EN 50041, 40 mm wide, with M12 device plug
- Plastic enclosures, 50 mm wide, with M12 device plug and M12 socket
- Metal enclosures, 56 mm wide, with M12 device plug and M12 socket
Display
The switches have a status display with three LEDs:
- LED 1 (yellow): F‑IN1
- LED 2 (yellow): F‑IN2
- LED 3 (green/red): AS‑i/FAULT
Connection
Connection to the AS-Interface is by means of a 4-pin M12 device plug (plastic version) connected to the yellow AS-Interface bus cable.
The wide enclosures (50 or 56 mm) also have an M12 socket for connecting a second position switch. In this way, SIL 3 according to IEC 62061/IEC 61508 or PL e according to ISO 13849‑1 is reached.
ENG_711660.xml
With the standard position switches, mechanical positions of moving machine parts are converted into electrical signals. Through their modular and uniform design and large number of variants, the devices can comply with practically all requirements in industry.
Devices are available with enclosure versions to suit the particular ambient conditions. Different control tasks can be performed with the contact blocks best suited for the particular purpose. And many different actuator variants are available to match the mechanical configuration of the moving machine parts. Dimensions, fixing points and characteristics are largely according to the EN 50041 or EN 50047 standards.
The devices are suitable for use in any climate.
Standards
The switches comply with IEC 60947‑1 (Low-Voltage Controlgear, General) and IEC 60947‑5‑1 (Electromechanical Control Circuit Devices).
The mechanical design of the switch corresponds to the requirements of the fail-safe principle according to ISO 14119.
Approvals
AS-Interface according to IEC 62026‑2
The 3SF1 position switches are approved according to UL 508, UL 50 and UL 746-C.
Safety circuits
Standard IEC 60947‑5‑1 requires positive opening of the NC contacts. In other words, for the purposes of personal safety, the assured opening of NC contacts is expressly stipulated for the electrical equipment of machines in all safety circuits and marked in accordance with the standard IEC 60947‑5‑1 with the symbol (→).
With a 3SF1 safety switch with (→), SIL 2 according to IEC 2061/IEC 61508 or PL c according to ISO 13849‑1 can be attained if the corresponding fail-safe evaluation units are selected from the ASIsafe program and correctly installed.
If a second 3SF1 safety switch with (→) is used, SIL 3/PL e can be attained.
Evaluation of safety functions
Safety Evaluation in the TIA Selection Tool
The safety evaluation for the IEC 62061 and ISO 13849-1 standards is performed quickly and easily, directly in the TIA Selection Tool. In addition to the fast and safe calculation of machine safety functions – from the definition of the system structure to the selection of components – this enables shared data management during all project phases. Take the next step in the digital design of machinery and equipment with Safety Evaluation in the TIA Selection Tool.
In addition, the functionalities of the proven Safety Evaluation Tool are still available. It determines the achieved safety integrity (SIL/PL) step-by-step. You receive the results as a standards-compliant report that can be integrated in the documentation as proof of safety.
For more information, see www.siemens.com/safety-evaluation-tool.
