Manual MRM3-2 GB
Woodward
TD_MRM3-2_09.08_GB_Rev.New
37
5.10.4 Fault Memory
In case of actuation or tripping of the relay, the fault values and times are stored in a voltage fail-
safe way. The MRM3-2 has a fault value memory covering up to 25 fault events. If this number is
exceeded, the eldest data set is then overwritten.
Besides the tripping values, the LED states are also saved for fault indication.
Inquiry of the fault memory
When the <-> push-button is pressed during normal measuring value indication, the fault data is
displayed.
FLT1
last
fault
FLT2
fault before last
etc.
By pressing <+> the respective fault can be selected.
During fault value indication FLT
•
it can be changed over to another fault data set by pressing <+> or <->
•
it is displayed, which of the parameter sets was active during the event
•
the LEDs are flashing according to the stored pick-up values/trip information, i.e. LEDs
showing a permanent light when the trip occurred, start to flash in order to indicate that is
was a past fault condition. Those LEDs, which were flashing when the trip occurred,
(element was actuated) are flashing briefly
•
the individual fault measuring values for the respective fault can be inquired by pressing
<SELECT/RESET>
If the relay has not been reset after tripping (TRIP is displayed), measuring values cannot be indi-
cated.
The fault memory can be cleared by pressing the button combination <SELECT/RESET> and <->
for about 3s. In the display „wait“ is shown.
Trigger signal for the fault memory
There are three trigger signals for the fault recorder
1.
End of a starting phase,
2.
A tripping signal,
3.
End of a protection excitation in OPERATING mode
depending on which event has occurred, the following values are recorded.
1. Values recorded at the end of a starting phase
•
max. staring current in Phase 1,
•
max. staring current in Phase 2,
•
max. staring current in Phase 3,
•
Earth current E,
•
Load-unbalance current I2,
•
Temperature
equivalent
ϑ
in % at this time,
•
Change in the temperature equivalent
ϑ
in % during the starting phase
•
Duration of start in s,
•
Date and time.
2. Values recorded after an excitation
•
Peak current during this excitation in Phase 1,
•
Peak current during this excitation in Phase 2,
•
Peak current during this excitation in Phase 3,
•
Peak current during this excitation in the earth current path
•
Peak current during this excitation for load unbalance
•
Temperature
equivalent
ϑ
in % at this time,
•
Date and time.
