Specifications

AS-Interface
ASIsafe
3SF1 position switches
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Siemens IK PI · 2012
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■ Overview
The 3SF1 position switches with safety-oriented communication
can be directly connected using the AS-Interface bus system.
The safety functions no longer have to be conventionally wired
up.
With the 3SF1 position switches the ASIsafe electronics are inte-
grated in the switch enclosure.
Examples of selection options in the modular system
Modular system
The 3SF1 1.4 and 3SF1 2.4 position switches are built as a
modular system, which consists of the basic switch in different
versions and a drive, which must be ordered separately. Thanks
to the modular design of the switch the end user can select the
right solution for his application from numerous versions and
install it himself 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 plug
• Metal enclosures according to EN 50041, 40 mm wide,
with M12 plug
• Plastic enclosures, 50 mm wide, with M12 plug and M12
socket
• Metal enclosures, 56 mm wide, with M12 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 connected to the yellow
AS-Interface bus cable by means of a 4-pole M12 plug
(plastic version).
The wide enclosures (50 or 56 mm) also have an M12 socket for
connecting a second position switch. Category 4 according to
EN 954-1 is thus achieved.
Benefits
The new generation of 3SF1 position switches offers:
• ASIsafe Electronics integrated in the enclosure,
with low power consumption < 60 mA
• An extensive range of actuators
• Status display with three LEDs
Operating conditions
With the standard position switches, mechanical positions of
moved machine parts are converted into electrical signals.
Through their modular and uniform design and large number of
versions, the devices can meet practically all requirements in
industry.
Devices are available with enclosure versions to suit the
particular ambient conditions. Different control tasks can be per-
formed with the best contact blocks suited for the particular
purpose. And many different actuator versions are available to
match the mechanical configuration of the moved machined
parts. Dimensions, fixing points and characteristics are largely in
accordance with the EN 50041 or EN 50047 standards.
The devices are suitable for use in any climate.
Standards
The switches comply with the standards IEC 60947-1
(Low-Voltage Switchgear and Controlgear, General) and
IEC 60947-5-1 (Electromechanical Control Circuit Devices).
The mechanical design of the switch corresponds to the require-
ments of the failsafe principle according to EN 1088.
Approvals
AS-Interface according to EN 50295 and IEC 62026-2.
With a 3SF1 position switch it is possible to achieve category 2
according to ISO 13849-1 (EN 954-1) or SIL 1 according to
IEC 61508.
Categories 3 or 4 according to ISO 13849-1 (EN 954-1) or SIL 2
or 3 according to IEC 61508 can be achieved by using a second
3SE5 position switch.
The 3SF1 position switches are approved according to UL 508,
UL 50 and UL 746-C.
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© Siemens AG 2011