TB MRI(K)3-C 03.02 E
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5.11 Additional functions
5.11.1Blocking the protection functions
Blocking of the protective functions:
The
MRI(K)3-C
is equipped with a blocking function that
can be parameterized arbitrary. Connecting supply
voltage to terminals at a assigned digital blocking of
those functions which were selected by the user takes
place.
It is possible to choose between two types of protective
blocking:
1.
Blocking of the individual protection stages. The ex-
citation of the blocked protection stage is blocked..
2.
Blocking of the individual tripping stages. The indi-
vidual protection stages are excited and the set
tripping time expires. Tripping only takes place
when:
a)
the voltage at the blocking input is reduced;
b)
the voltage at the blocking input is applied, the
tripping time and the blocking time have expired.
(refer to chapter 5.7.1)
Parameter setting is to be carried out as follows:
•
After the <ENTER> and <TRIP> keys have been ac-
tuated simultaneously, the display shows the text
"PR_B" (the protection stages are blocked) or "TR_B"
(the tripping stages are blocked).
•
The settings can be changed by actuating the keys
<+> or <->. In this procedure, the LEDs I>; I>>;
IE>; IE>> are simultaneously alight in case of pro-
tective blocking "PR_B" and LEDs tI>; tI>>; tIE>,
tIE>> simultaneously emit light in case of trip block-
ing "TR_B".
•
Actuation of the <ENTER> key with a one-time entry
of the password will store the set function.
•
After this actuate the <SELECT/RESET> key to call
up the first blockable protection function.
•
The display will show the text "BLOC" (the respec-
tive function is blocked) or "NO_B" (the respective
function is not blocked.
•
Actuation of the <ENTER> key will store the set func-
tion.
•
By pressing the <SELECT/RESET> pushbutton, all
further protective function that can be blocked are
called one after the other.
After selection of the last blocking function renewed
pressing of the <SELECT/RESET> pushbutton switches to
the assignment mode of the output relays.
Function
Display LED/Colour
Blocking of the protection
stage
PR_B
I>; I>>; I
E
>;
I
E
>>
Blocking of the trip function TR_B
t
I
>; t
I
>>; t
IE
>;
t
IE
>>
I>
Overcurrent
NO_B
I> green
I>>
Short circuit
BLOC
I>> green
I
E>
Earth current
1
st
element
NO_B
I
E>
green
I
E>>
Earth current
2
nd
element
NO_B
I
E>>
green
t
CBFP
Circuit breaker
failure protection
NO_B
CB green
DI+Trip
Ext. tripping
NO_B
DI+Trip
Table 5.3: Default settings of both parameter sets
5.11.2
Assignment of the output relays
Unit
MRI3
has five output relays. The fifth output relay is
provided as permanent alarm relay for self supervision is
normally on. Output relays 1 - 4 are normally off and
can be assigned as alarm or tripping relays to the cur-
rent functions which can either be done by using the
push buttons on the front plate or via serial interface
RS485. The assignment of the output relays is similar to
the setting of parameters, however, only in the assign-
ment mode. The assignment mode can be reached only
via the blocking mode.
By pressing push button <SELECT/RESET> in blocking
mode again, the assignment mode is selected.
The relays are assigned as follows: LEDs I>, I>>, I
E
>,
I
E
>> are two-coloured and light up
green
when the out-
put relays are assigned as
alarm relays
and
red
as
tripping relays
. In case of the
MRIK3-C
models the
LEDs I>; I>>; I
E
> and I
E
>> always light up in conjunction
with t>.
In addition, the LED
→←
also lights up with each ad-
justment. Green means forward and red backward di-
rection.
Definition:
Alarm relays
are activated at pickup.
Tripping relays
are only activated after elapse of the
tripping delay.
