3UG4622-1AW30 Datasheet, PDF (109/114 Pages) List of Unclassifed Manufacturers – Monitoring and Control Devices

3TK28 Safety Relays
With contactor relay enabling circuits
■ Design
■ Function
The solid-state safety combinations can be used in
EMERGENCY-STOP devices according to EN 418 and in safety
circuits according to EN 60204-1 (11.98), for example, for
moving covers and protective doors. Depending on the device
type and the external circuit, the maximum category that can be
achieved is Category 4 of EN 954-1 or SIL 3 according to
IEC 61508.
With these devices, solid-state safety relays are connected with
contactor relays. The combination is supplied as a complete
self-contained unit, fully wired up and tested, for snapping onto
a standard mounting rail. This unit combines the advantages of
a solid-state safety relay and those of contactor relays with
positively-driven contacts in a single device. It has been certified
by the appropriate authorities as a complete unit.
Basic units, Category 3
The solid-state safety relays 3TK28 50, 51 and 52 have two
contactor relays snapped onto the safety solid-state unit as
floating switch blocks. Three LEDs indicate the operating status
and the function. During operation, all internal circuit elements
are monitored cyclically for faults. Up to Category 3 according to
EN 954-1 is achieved, depending on the external circuit.
The electronics (based on the example of a 3TK28 41)
7 The internal circuit is configured with redundancy and
diversity. The processors monitor each other dynamically.
7 The output drivers are also redundant and diverse. They are
monitored by a cyclic self-test.
7 All sensor signals are dynamically tested. This enables faults
to be detected on the sensors, wires (cross-circuit) etc.
7 The field-effect transistor (FET) is switched by both
processors. The output driver must be activated
simultaneously by one of the two processors. Only then, the
voltage is connected safely from power supply terminal A1 to
output terminals 14 + 24.
7 All solid-state switches (FET + output driver) are dynamically
monitored by the processors.
7 The required functionality (1-channel or 2-channel), monitored
start or autostart, EMERGENCY-STOP, protective door and
cascading is set by means of jumpers at the connection
terminals.
Y11 Y12 Y35 Y21 Y22 Y32 Y34 1
A1
Basic units, Category 4
The 3TK28 53 solid-state safety relay has two contactor relays
snapped onto the safety solid-state units as floating switch
blocks, as well as a safe solid-state output, a safe input for
cascading and one input for normal switching duty. Three LEDs
µC1
indicate the operating status and the function.
FET
µC2
During start-up, the equipment runs through a self-test in which
the internal electronics are checked for correct functioning.
During operation, all internal circuit elements are monitored
cyclically for faults.
Output driver
Expansion units and the 3TK28 30, 3TK28 56/57, 3RA7 11, 12,
13, 14 devices as well as external actuators or loads can be
connected using the safe solid-state output (terminal 2).
Cascading with the 3TK28 41/42/45/53 safety combinations as
well as with the 3RA7 11 load feeder is also possible using the
safe solid-state output (terminal 2).
A2
14 24
Installation
For snap-on mounting on 35 mm standard mounting rail
according to EN 50022. Screw fixing is also possible for the
devices by means of 2 additional 3RP19 03 push-in lugs.
Siemens LV 1 T · 2006 _7/109