Safety Integrated - Industry - Siemens

Ex. No. Protective door monitoring with automatic start Category 4
2.12
acc. to EN 954-1 with/without operational switching
with a safety fuseless load feeder 3RA7
Function
Description of the functionality
This Safety Functional Example describes a mechanically isolating
protective mechanism in the form of a protective door.
The most frequently used solution for plants and machines to
secure hazardous areas is mechanically isolating protective
equipment or access hatches. In this case, the function is to
monitor unauthorized entry into plant and system areas as
well as to prevent potentially hazardous machine functions if
the protective equipment - in this case protective door - is not
closed.
Position switch with
separated actuator
Actuator
Protective door opened Protective door closed
The protective door is monitored by two SIRIUS position
switches with positively-opening contacts using a safety fuseless
load feeder according to Category 4 in compliance with
EN 954-1. If this protective door is opened, the load feeder
safety shuts down (de-activates) the contactors, connected in
series, with its positively-driven contacts according to stop
Required components
Hardware components
Note
The functionality was tested using the specified hardware
components. Products that are similar but deviate
from the list above can be used (e.g. a different safety
load feeder). However, in this case, please carefully note
that it may be necessary to make modifications as to
how the hardware components are connected-up (e.g.
another connection assignment).
50 Functional Example No. CD-FE-I-016-V10-EN
G_FB_XX_038
Category 0 in compliance with EN 60204. In this particular example,
a drive is stopped. If the protective door is closed and
after the position switch and downstream contactors have
been checked, then the drive automatically starts. It is possible
to operationally switch (in/out) the contactors. Either a
floating (electrically isolated) contact is connected between
terminal 3 and terminal 4 (refer to „Wiring of the hardware
components“ page 51) or a non-floating (non-electrically isolated)
output (24 V DC) - e.g. from a standard PLC - is connected
at terminal 4. The operational switching has a lower
priority than the safety function. If the operational switching
is no longer required, a wire link (jumper) should be connected
between terminal 3 and terminal 4.
Note
The position switches must be arranged so that they are
not damaged when they are approached and passed.
This is the reason that they may not be used as mechanical
endstop.
Advantages/customer benefits
■ Pure hardware engineering without having to configure/program
software
■ A low scope of simple wiring
■ Space-saving design using our compact safety relay
■ Can be simply expanded using expansion devices
Component Type MRPD / Ordering data Qty Manufacturer
SIRIUS
position switch
Position switch with separate actuator 3SE2 243-0XX40 2 Siemens AG
Actuator for
position switch
Radius actuator 3SX3 228 2
Safety load feeder 3RA7 3RA7112-4CA26-0AB4 1