•
The machine must switch to the safe state at any time if at least one of the two
OSSDs switches to the OFF state
•
Prevent the formation of a potential difference between the load and the protec‐
tive device. If you connect loads to the OSSDs (switch outputs) that then also
switch if controlled with negative voltage (e.g., electro-mechanical contactor with‐
out reverse polarity protection diode), you must connect the 0 V connections of
these loads and those of the corresponding protective device individually and
directly to the same 0 V terminal strip. In the event of a fault, this is the only way to
ensure that there can be no potential difference between the 0 V connections of
the loads and those of the corresponding protective device.
Figure 15: No potential difference between load and protective device
DANGER
Hazard due to lack of effectiveness of the protective device
In the case of non-compliance, it is possible that the dangerous state of the machine
may not be stopped or not stopped in a timely manner.
Downstream contactors must be positively guided and monitored depending on appli‐
cable national regulations or required reliability of the safety function.
b
Make sure that downstream contactors are monitored (external device monitoring,
EDM).
NOTE
Because the protective device does not have integrated external device monitoring, this
must be implemented in the external control, if required.
Requirements for the electrical control of the machine
Both outputs are short-circuit protected to 24 V DC and 0 V. When the protective field
is clear, the OSSDs are in the ON state. When a switch-off condition is present (e.g.,
interruption in the light path), the OSSDs are in the OFF state. In the event of a device
fault, at least one OSSD is in the OFF state.
The protective device complies with the rules for electromagnetic compatibility (EMC)
for the industrial sector (Radio Safety Class A).
Radio interference cannot be ruled out when used in residential areas.
The following requirements are met:
•
The external voltage supply of the protective device must be capable of buffering
brief power failures of 20 ms as specified in IEC 60204-1.
•
The power supply unit must ensure safe isolation according to IEC 61140
(SELV/PELV). Suitable power supply units are available as accessories from SICK.
PROJECT PLANNING
4
8014276/1DCM/2022-10-27 | SICK
O P E R A T I N G I N S T R U C T I O N S | deTec2 Core
23
Subject to change without notice
