Manual MRG3
SEG Electronics GmbH
DOK-TD-MRG3, Rev. D
53
5.9 Additional functions
5.9.1 Blocking of protection functions and assignment of the output relays
The blocking function of the MRG3 can be set according to requirement. By applying the aux. volt-
age to D8/E8, the functions chosen by the user are blocked. Setting of the parameter should be
done as follows:
When pressing push buttons <ENTER> and <TRIP> at the same time either the message
"BLOC" (i.e. the respective function is blocked) or "NO_B" (i.e. the respective function is
not blocked) are displayed. The LED that is allocated to the first protection function U<
lights with U + 1 + <.
By pressing push buttons <+> <-> the displayed value can be changed.
The changed value is stored by pressing <ENTER> and entering the password.
By pressing the <SELECT/RESET> push button, any further protection function which can
be blocked is displayed.
If the <SELECT/RESET> key is actuated again, the blocking menu is left and the
assignment mode is accessed^.
Function
Description
Display
LED
U<
Under voltage step 1
BLOC
U + 1 + <
U<<
Under voltage step 2
BLOC
U + 2 + <
U>
Overvoltage step 1
NO_B
U + 1 + >
U>>
Overvoltage step 2
NO_B
U + 2 + >
f1<(>)
Frequency step 1
BLOC
f + 1 + <(>)
f2<(>)
Frequency step 2
BLOC
f + 2 + <(>)
f3<(>)
Frequency step 3
NO_B
f + 3 + <(>)
Vector surge
BLOC
/df*
df/dt
Frequency changing rate
BLOC
/df*
I>
Over current
NO_B
I + 1 + >
I>>
Short circuit
BLOC
I + 2 + >
U
0
>**
Residual voltage step 1
NO_B
U
0
+ 1 + >
U
0
>>**
Residual voltage step 2
NO_B
U
0
+ 2 + >
I
E
>
Earth current step 1
NO_B
I
E
+ 1 + >
I
E
>>
Earth current step 2
NO_B
I
E
+ 2 + >
tCB
Circuit breaker failure protection
NO_B
CB
* only one of the two functions can be activated
**not available in MRG3-IER
Table 5.4: Blockage function for two parameter sets
After the assignment mode has been activated, first the LEDs U + 1 + < light up. Now, up to four
output relays can be assigned to the under voltage element U< as alarm relays. At the same time
the selected alarm relays for under voltage element 1 are indicated on the display. Indication "1_ _
_" means that output relay 1 is assigned to this under voltage element. When the display shows "_
_ _ _", no alarm relay is assigned to this under voltage element. The assignment of output relays 1
- 4 to the current elements can be changed by pressing <+> and <-> push buttons. The selected
assignment can be stored by pressing push button <ENTER> and subsequent input of the pass-
word. By pressing push button <SELECT/RESET>, LEDs U1 + 1 + < + t> lights up. The output re-
lays can now be assigned to this voltage element as tripping relays. Relays 1 - 4 are selected in the
same way as described before. By repeatedly pressing of the <SELECT/RESET> push button and
assignment of the relays all elements can be assigned separately to the relays. The assignment
mode can be terminated at any time by pressing the <SELECT/RESET> push button for some time
(i.e. approx.. 3 s).
