Operating Instructions
Chapter
6
UE 440/470
8 010 432/P097/14-03-05
© SICK AG • Industrial Safety Systems • Germany • All rights reserved
51
Electrical installation
6.2.5
Dual channel emergency stop
You can use a complementary (
) or equivalent (
) button for a dual channel emergency
stop.
$
With complementary evaluation, the N/C contact must always be connected to the first
channel.
$
With equivalent input evaluation, an emergency stop input device with two N/C contacts
must be used.
$
You can connect a dual channel emergency stop for each safety application.
6.2.6
Key-operated switch for bypass
The bypass function may only be activated by a key-operated switch with an automatic
reset and two levels or by two input signals that are independent of each other, e.g. two
position switches.
You can use a complementary
or equivalent
switching key-operated switch.
$
Mount the key-operated switch for bypass in such a way that the hazardous point is
completely visible when the key-operated switch is used.
$
With equivalent evaluation, the contacts of the key-operated switch for bypass must be
dual channel N/O contacts.
$
With complementary evaluation, the N/O contact must always be connected to the first
channel.
$
The key-operated switch for bypass must have volt-free contacts.
6.2.7
Reset button
You can connect separate reset buttons for each of the two safety applications which you
can implement with the safety controller.
Use single channel N/O contacts for reset buttons.
Fig. 18: Examples for
connection of a dual channel
emergency stop
Notes
Fig. 19: Examples for the
connection of a key-operated
switch for bypass
Notes
Fig. 20: Example for
connection of a reset button