Fault Tolerance; Protection Of The Power Supply - SICK T4000 Bedienungsanleitung

5
Chapter
Note
154
© SICK AG • Industrial Safety Systems • Germany • Subject to change without notice • 8012206/UC32/2010-11-15
Electrical connection
 Equipment that is a powerful source of interference
must be physically separated from the input and output
circuits for the signal processing. The safety circuits
should be laid as far as possible from the cables for the
power circuits.
5.2

Fault tolerance

 If the device does not appear to function after the
application of the operating voltage (e.g. green STATE
LED does not flash), the safety switch must be returned
to the manufacturer unopened.
 The operating voltage U
The contacts IA/IB and OA/OB are short-circuit protec-
ted.
 A cross-circuit between IA and IB or OA and OB will be
detected by the switch. A cross-circuit in the cable can
be prevented by laying the cable with protection.
 A short-circuit from IA and IB to U
laying the cable with protection.
5.3

Protection of the power supply

The power supply must be protected as a function of the
number of switches and the current required for the
outputs. The following rules apply here:
Max. current consumption of a single switch I
I = I + I + I
max UB OUT
I = Switch operating current (80 mA)
UB
I = Signal output load current (max. 200 mA)
OUT
I = Safety outputs load current
OA+OB
OA + OB (2 x max. 400 mA)
Max. current consumption of a chain of switches P I
P I = P I + n x (I
max OA+OB
n = Number of switches connected
A maximum of 20 T40-E01 safety switches can be
connected in series.
is reverse polarity protected.
B
OA+OB
+ I )
UB OUT
Operating Instructions
T4000 Direct Unicode
can be prevented by
B
max
max