•
Prevent the formation of a potential difference between the load and the protec‐
tive device. If you connect loads to the OSSDs (safety 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 12: 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 applic‐
able national regulations or required reliability of the safety function.
b
Make sure that downstream contactors are monitored (external device monitoring,
EDM).
The OSSDs are short-circuit protected to 24 V DC and 0 V. If the safety locking device is
locked, the OSSDs signal the ON state with the HIGH signal level (non-isolated). If the
safety locking device is unlocked or there is a device fault, the OSSDs signal the OFF
state with the LOW signal level.
Do not use a control system with clocking or switch off the clocking function of the con‐
trol system. The device generates its own test pulses at the OSSDs. A downstream con‐
troller must tolerate these test pulses, which can have a length of up to 1 ms. The test
pulses are also output when the OSSDs are switched off. Depending on the sluggish‐
ness of the downstream device (controller, relay, etc.), this can lead to short switching
processes.
For inductive loads, the OSSDs must be protected with a freewheeling diode. RC sup‐
pressors must not be used:
4.4.3
Application diagnostic outputs
Door application diagnostic output (Out AUX DOOR)
The signal of the door application diagnostic output changes as soon as the actuator is
moved into or leaves the response range of the safety switch. In other words, the output
signal changes when the protective device is opened and closed. This is not a safety
output.
4
PROJECT PLANNING
20
O P E R A T I N G I N S T R U C T I O N S | TR110 Lock
8023119/15LY/2019-10-28 | SICK
Subject to change without notice
