24
TB MRI3-ITE(R) 12.00 E
5.7
Additional functions
5.7.1
Blocking of the protective functions
Blocking of the protective functions:
The
MRI3-ITE(R)
is equipped with a blocking function
that can be parameterized arbitrary. Connecting sup-
ply voltage to terminals D8/E8 blocking of those func-
tions which were selected by the user takes place.
It is possible to choose between two types of protec-
tive blocking:
1.
Blocking of the individual protection stages. The
excitation of the blocked protection stage is
blocked..
2.
*)
Blocking of the individual tripping stages. The
individual protection stages are excited and the
set tripping time expires. Tripping only takes place
when:
a)
the voltage at the blocking input D8/E8 is re-
duced;
b)
the voltage at the blocking input D8/E8 is ap-
plied, the tripping time and the blocking time
have expired. (refer to Chapter 5.4.19)
Parameter setting is to be carried out as follows:
•
*)
After the <ENTER> and <TRIP> keys have
been actuated 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
protective blocking "PR_B" and LEDs tI>; tI>>; tIE>,
tIE>> simultaneously emit light in case of trip
blocking "TR_B".
•
Actuation of the <ENTER> key with a one-time en-
try 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
function.
•
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 re-
newed pressing of the <SELECT/RESET> pushbut-
ton switches to the assignment mode of the output
relays.
*) Only MRI3-IT/ITE
Function
Display
LED/Colour
I
B,A
Temperature
NO_B
I
B,A
red
I
B,T
Temperature
NO_B
I
B, T
red
I>
Overcurrent
NO_B
I> red
I>>
Short circuit
BLOC
I>> red
I
E>
Earth current
First element
NO_B
I
E>
red
I
E>>
Earth current
Second element
NO_B
I
E>>
red
tCBFP
Circuit breaker
failure protection
NO_B
CB yellow
Table 5.3: Defaults settings of blocking functions
Assignment to the output relays:
Unit
MRI3-ITE
has five output relays. The fifth output re-
lay is provided as permanent alarm relay for self su-
pervision is normally on. Output relays 1 - 4 are nor-
mally off and can be assigned as alarm or tripping re-
lays to the frequency functions which can either be
done by using the pushbuttons 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 assignment mode. The assignment mode
follows the blocking mode.
The relays are assigned as follows:
LEDs I
B,A
, I
B,T
, I>, I>>, I
E>
and I
E>>
are two-coloured and
light up
green
when the output relays are assigned as
alarm relays
and
red
as
tripping relays
.
Definition:
Alarm relays
are activated at pickup of the relay.
Tripping relays
are only activated after elapse of the
tripping delay.
After the relay assignment mode has been activated
the LED I> lights up green. Now one or several of the
four output relays can be assigned to element I> as
alarm relays. At the same time the selected alarm re-
lays for element I> are indicated on the display. Indi-
cation "1_ _ _" means that output relay 1 is assigned
to this current element. When the display shows
"_ _ _ _", no alarm relay is assigned to this current
element.
