SEG Electronics GmbH
Manual MRG3
58
DOK-TD-MRG3, Rev. D
5.10.6 Indication of fault data
All faults occurrences detected by the relay are indicated on the front plate optically. For this pur-
pose, the MRG3 is equipped with the three LEDs (L1, L2, L3) and the function LEDs U, f, I, IE, U0,
1, 2, 3, <, >, t> are equipped at MRG3. Not only fault messages are transmitted, the display also
indicates the activated protection function. If, for example an overvoltage occurs, the corresponding
phase LEDs L1 and/or L2 and/or L3 will light up as well as LEDs U + 1 + <. After expiry of the trip-
ping time the LEDs are lit permanently. If the threshold of the respective protection function falls
below the adjusted tripping time, this will be indicated by a short flashing up of the LEDs.
The display shows “TRIP” when the adjusted tripping time has expired. Then, it is possible to indi-
cate the stored tripping values by pressing the push-button <SELECT/RESET> (see also chapter
4.1.1 of the MR
– Digital Multi-function Relay)
5.10.7 Fault recorder
When the relay is energized or the relay has tripped, all fault data and times are stored in a non-
volatile memory manner.
Excitation
: The highest value measured during excitation phase is stored.
Tripping: All values measured at the moment of tripping are stored.
If an error is not immediately switched off after tripping, further fault data will be recorded.
The MRG3 is provided with a fault value recorder for max. 16 fault occurrences. In the event of ad-
ditional trippings always the oldest data set is written over.
For fault indication not only the trip values are recorded but also the status of LEDs. Fault values
are indicated when push buttons <-> or <+> are pressed during normal measuring value indication.
Normal measuring values are selected by pressing the <SELECT/RESET> button.
When then the <-> button is pressed, the latest fault data set is shown. By repeated press
ing of the <-> button the last but one fault data set is shown etc. For indication of fault data
sets abbreviations FLT1, FLT2, FLT3, ... are displayed (FLT1 means the latest fault data
set recorded). At the same time the parameter set that was active at the occurrence is
shown.
By pressing <SELECT/RESET>, each individual measured fault value can be called up.
By pressing <+> it can be scrolled back to a more recent fault data set. At first FLT8, FLT7,
are always displayed.
When fault recording is indicated (FLT1 etc.), the LEDs flash in compliance with the stored
trip information, i.e. those LEDs which showed a continuous light when the fault occurred
are now blinking to indicate that it is not a current fault condition. LEDs which were blinking
during trip conditions, (element had picked up) just briefly flash.
If the relay is still in trip condition and not yet reset (TRIP is still displayed), measuring
values can not be shown.