Further topics
•
4.4.1
Restart interlock
Overview
The restart interlock prevents the machine from automatically starting up, for example
after a protective device has responded while the machine is operating or after chang‐
ing the machine’s operating mode.
Depending on the regulations which apply at the place of installation, a restart interlock
may be required.
The protective device does not have an internal restart interlock. You must therefore
implement a restart interlock externally via the circuitry or the control if needed, e.g. in
connection with the SICK RLY3-OSSD2 / RLY3-OSSD3 safety relay.
Principle of operation
Before the machine can be restarted, the operator must reset the restart interlock.
1
3
2
4
Figure 16: Schematic representation of operation with restart interlock
The dangerous state of the machine (
1
) is brought to an end if the light path is inter‐
rupted (
2
) and is not re-enabled (
3
) until the operator presses the reset pushbutton
located outside the hazardous area (
4
). The machine can then be restarted.
Depending on applicable national regulations, a restart interlock must be available if it
is possible to stand behind the protective device. Observe IEC
60204-1.
4.4.2
External device monitoring (EDM)
Overview
The external switching elements (external device monitoring, EDM) must be inspected
in line with the regulations which apply at the place of installation or the required
reliability of the safety function.
External device monitoring (EDM) monitors the status of downstream contactors.
Important information
NOTE
Because the protective device does not have integrated external device monitoring, this
must be implemented in the external control, if required.
Prerequisites
•
Positively guided contactors are used for shutting down the machine.
4
PROJECT PLANNING
24
O P E R A T I N G I N S T R U C T I O N S | deTec2 Core
8014276/1DCM/2022-10-27 | SICK
Subject to change without notice
