Mechanical and electrical configuration
98
X20 system User's Manual 3.10
3.21.6 General notices
3.21.6.1 Installation notes
Modules must be protected against impermissible dirt and contaminants. The maximum permissible level of dirt and
contaminants is Pollution Level II as specified in the IEC 60664 standard. This can be achieved through installation
in a control cabinet that provides IP54 protection.
When using the operating principle, uncoated X20 modules must not be operated in condensing relative humidity
or with ambient temperatures below 0°C.
3.21.6.2 Timing
3.21.6.2.1 Worst case scenario
A maximum cutoff time of 500 ms must be assumed for the potential group for worst case scenarios. This time is
needed to guarantee that energy stored within the module is discharged and the actuators are cut off in worst case
scenarios. The cutoff times needed for the upstream external safety relay and actuator must also be added.
Worst case conditions for "Output = Off"
•
Digital output: <5 V
•
Analog output: <100 mV
3.21.6.2.2 Load-dependent cutoff time
The actual duration of cutoff can be calculated with the following formula.
t
spec
Actual cutoff time
C
tot
Total capacity of all modules in the potential group. (e.g. 10 modules 47 µF + 3 modules with 150 µF → Ctot = 920 µF)
U
in
Supply voltage
U
off
Voltage, if Output = Off
I
load
External load
Table 8: Parameter descriptions
Module
Module's internal capacity
X20MM2436
X20SM1426
X20SM1436
150 µF
Other modules
1)
47 µF
1)
Only modules from section 3.21.5.1 "Suitable modules".
If the result is t
spec
= >500 ms, then the worst-case assumption from section 3.21.6.2.1 "Worst case scenario" applies.
Information:
•
The calculated load-dependent cutoff time must be verified by a test measurement!
•
At the time a safety function is requested, there is no guarantee that the outputs used to cal-
culate the load-dependent cutoff time are enabled. For example, if an output is disabled at the
time of a request, then the respective internal capacities in the module will not be discharged
in the calculated time (t
spec
). The worst-case time of 500 ms should be taken into account in this
situation. If the output is enabled from the functional application (shown in the sketch as the
interval t
application
) during the worst-case time (<500 ms), then the output subsequently remains
enabled for the calculated time.
Summary of Contents for X20 System
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