Memory - Siemens SIRIUS 3RT Series System Manual

8.8.1.6

Memory

Definition of memory
The "Memory" setting controls how the device behaves following a shutdown due to a fault
and subsequent return to the normal range.
There are two possible settings:
● Automatic reset (Memory = O)
If the device is set to automatic reset, the switching contact will respond once the normal
range plus the hysteresis threshold have been reached. The red FAULT LED goes out.
The overshoot or undershoot which triggered the response is not saved.
The hysteresis is set to a fixed value of 6.25% of the set value.
● Manual RESET (Memory = I)
If manual RESET is selected, the switching contact remains in the current switching state
even if the load current returns to a permissible value.
Note
Reset with manual RESET
This saved fault condition can be reset by briefly switching to Memory = O or by
disconnecting and then reconnecting the supply voltage.
Factory setting
The device is factory-set to automatic reset.
Changes to settings
Move the slide switch (Memory) to toggle the device between automatic reset and manual
RESET.
Reference
For more information, see the chapter titled Hysteresis (Page 718).
SIRIUS Innovations
System Manual, 01/2011, A8E56203870002-03
SIRIUS 3RR2 current monitoring relays
8.8 Operation
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