Siemens SITOP PSU8600 Manual page 131

Parameter
Dead time for system over-
load alarm
Dead time for buffer opera-
tion alarm
● Prioritized buffering of output 1
When the power fails, output 1 of the basic device can be prioritized so that it is still
supplied.
Prioritizing output 1 means that the longest possible buffer time is ensured for this output.
If output 1 is prioritized, all of the remaining outputs are shut down at approximately half
of the nominally available buffer time for the remaining duration of the power failure.
LEDs "ON/OFF/RST" of the outputs that have been shut down are lit red.
Outputs 2 ... n, which are shut down when the power fails as output 1 has priority, are
automatically switched-on again when the line supply returns.
For the basic device, the typical buffer time is 15 ms, additional buffer modules extend
the buffer time.
● Parallel connection of output 1 and output 2 / output 3 and output 4
Two outputs of a basic device can be connected in parallel to supply a load branch with a
current that is higher than the continuous maximum current of an individual output of the
basic device. This increases the available current rating.
The switchover to parallel operation means that the outputs involved are synchronized
and controlled together.
● Prewarning threshold
When changes are made, the prewarning threshold for the summed current allows you to
quickly check the utilization of the overall system. This is especially of interest when
expanding the system. Using the prewarning threshold increases operational reliability.
Enter a value of "0 %" to deactivate the prewarning threshold.
● System start characteristics
In order to reduce the load on the overall SITOP PSU8600 power supply system as a
result of simultaneous switch-on current peaks of the loads at the various outputs, an on
delay between the outputs can be selected when switching on.
When the on delay is activated, the outputs are sequentially switched-on with a 25 ms or
100 ms delay time between the outputs, or load optimized.
When the variable on delay is activated, you can assign individual on delay times to the
individual outputs.
● Dead time for system overload alarm
A system overload alarm is only initiated if a continuous system overload occurs, which is
longer than the set dead time.
● Dead time for buffer operation alarm
A buffer operation alarm is only initiated if the power continuously fails for a time that is
longer than the set dead time.
PSU8600power supply systems
Manual, 04.2016, A5E35883207-7-76
Value range
0 - 60000 ms
0 - 1000 ms
Engineering and remote access
7.3 SIMATIC STEP 7 in the TIA Portal
Default setting
5000 ms
0 ms
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