Expansion units with integrated
safety technology
Instructions
WARNING:
HAZARDOUS VOLTAGE
CAN CAUSE ELECTRICAL SHOCK
AND BURNS.
DISCONNECT POWER BEFORE PROCEEDING
WITH ANY WORK ON THIS EQUIPMENT.
The devices must be installed in a switchgear cabinet with the IP32,
IP43 or IP54 degree of protection, depending on the ambient conditions.
IMPORTANT NOTICE
The products described herein are designed to be components of a customized
machinery safety-oriented control system. A complete safety-oriented system
may include safety sensors, evaluators, actuators and signaling components. It
is the responsibility of each company to conduct its own evaluation of the effec-
tiveness of the safety system using trained individuals. Siemens AG, its subsid-
iaries and affiliates (collectively "Siemens") are not in a position to evaluate all
of the characteristics of a given machine or product not designed by SIEMENS.
Siemens accepts no liability for any recommendation that may be implied or
stated herein. The warranty contained in the contract of sale by Siemens is the
sole warranty of Siemens. Any statements contained herein do not create new
warranties or modify existing ones.
Application
The 3RA712/3/4 expansion unit can be used in conjunction with any 3TK28/
3RA7 basic unit. It serves to expand the release circuits.
accordance with
DIN EN 954-1 or SIL3 in accordance with IEC 61508 can be
achieved
, depending on the external connections
Functions and connections
The 3RA7121/2, 3RA7131/2 and 3RA7141/2 expansion units consist of an
adapter for rail mounting with integrated safety-oriented electronics, a circuit-
breaker and two series-connected contactors.
This combination forms a complete load feeder, wired and certified in the fac-
tory, which complies with type of coordination 1 or 2.
The 3RA7120, 3RA7130 and 3RA7140 expansion units without a circuit-breaker
are used for separate or fused mounting.
The operating status and the function are indicated by means of three LEDs.
When the device is started up, it executes a self-test to check that the internal
electronics are functioning correctly. All internal circuit components are moni-
tored for faults cyclically during operation.
Additional expansion units, e.g. 3TK2830/56/57 or 3RA712/3/4, as well as
external actuators or loads can be connected via the safe output 2. This output
can also be used for cascading with the 3TK2841/42/45/53 and 3RA711 devices.
It is important to ensure that the actuator or load and the expansion unit have
the same frame potential.
Please refer to the typical applications shown in Figs. IV to VII for the external
connections of the safety combination.
Use a power pack to IEC 60536 safety class III (SELV or PELV)
for the power supply!
Terminal
Operating
A1
assignments
voltage
A2
Outputs
L1/T1, L2/T2, L3/T3 Main circuits
Inputs
1
3
4
Output
2
2
Cable lengths for 2 x 1.5 mm
Figures
Figs. I / II:
Dimension drawings (dimensions in mm) / Installation
Internal connections: ¿ power supply unit, À sensor evaluation,
Fig. III:
Á driver for contactors, Â power section, Ã cascading input,
Ä terminals for operational switching, Å safe solid-state output
Fig. IV:
3TK2823 expanded with 3RA712/3/4, two-channel EMERGENCY STOP
with additional ON button, Cat 4 / SIL 3
Fig. V:
3TK2841 expanded with 3RA712/3/4, two-channel protective door
monitoring, autostart, Cat 4 / SIL 3
2
Safety category 4 in
.
L+
M
Cascading input
Supply for external switches
Input for operational switching
Safe solid-state output 24V DC / 1A
Max. 2000 m (total cable length for sensors)
Order No.: 3ZX1012-0RA70-1AA1
Fig. VI:
3RA711 expanded with 3RA712/3/4, two-channel EMERGENCY STOP
with additional ON button, Cat 4 / SIL 3
Fig. VII:
a: Without operational switching
b: With floating contact operationally switched
c: With non-floating contact operationally switched
Fig. VIII:
Release circuits
Operating states
LEDs
Operation
POWER RUN
FAIL
EMERGENCY
STOP
Self-test approx. 7 sec. on startup
Closed
Open
Only for 3RA713/4
Closed
Flashes
Open
Flashes
Faults
• Electronic defect
• Change in terminal
Flashes
assignment during
operation
• Short-circuit to L+,
Contactor welded
No supply voltage
Technical data / auxiliary circuit
Permissible ambient temperature T
Operation/storage
Degree of protection to EN 60 529
Rated insulation voltage U
i
Rated impulse withstand voltage U
Rated control supply voltage U
s
1)
Rated power
Operating range
Shock resistance
2)
Weight
Recovery time after EMERGENCY STOP
Recovery time after power failure
3)
Release time (EMERGENCY STOP)
Release time (power failure)
4)
Response time
5)
Dark time
Technical data / main circuit
Depends on the power section
1)
Only safety electronics, power loss of the power section must be added.
2)
Only adapter for rail mounting incl. safety electronics, weight of the power section must
be added.
3)
Opening delay of the contactors must be added.
4)
Closing delay of the contactors must be added.
5)
Safe outputs disconnected for test purposes; sufficiently slow actuators ars not affected.
For further data and accessories see Catalog NS K.
3RA712/3/4
IEC 60 439-1 (1999)
Operational
Contactors Output Cause
switching
Closed
On
On
Open
Off
-
Off
Off
Open
On
On
-
On
Off
Off
Off
u
-20 to +60 °C / -40 to +80 °C
IP 20
690 V
6 kV
imp
24 V DC
2 W
0.9 to 1.1 x U
s
5 g/11 ms
200 g
typically 400 ms
7 s
typically 25 ms
max. 100 ms
typically 40 ms
< 1 ms
English
Normal
operation
Contactors
deenergized
Open
EMERGENCY
STOP
Timeout
Timeout