Siemens 7UT51

8
Time Overcurrent Protection (50HS and 50/51)
7UT51 v3
106 PRIM-2330C
8.7 Events and Actions
Table describes the events that control and are
generated by the 50/51 and 50HS functions. They are
listed in the order that they are likely to occur, which is
roughly in numerical order by their event identification
number (shown in the “Event” column). The text in the
“LCD Abbreviation” column is the corresponding text
that will appear when viewing logs on the front panel
LCD display. In the “Oper” column, a letter “C” or “G”
indicates that the “Coming” and/or “Going” events are
logged in the Operational Log, while if in the “Fault”
column they indicate that the events are logged in the
open fault log. A letter in the “In/Out” column indicates
that the event can be controlled by a binary-signal
input (“I”), control an LED and/or signal contact (“S”),
and/or control a trip contact (“T”).
Table 8.1
Events Related to Time Overcurrent Protection (50/51 and 50HS)
Time Overcurrent Protection (50/51 and 50HS) Occurrence LCD Abbreviation Event Oper Fault In/Out
Change in Operational Status
When the operational status of the 50/50HS/51 function changes,
a going
-
event for the old status occurs followed by a coming
-
event
for the new status. The normal operational status is set in
Address 2101.
BU OFF
BU ACTIVE
BU BLOCK
2401
2403
2402
C
C
C
G
G
G
S
S
S
A binary input can temporarily change the operational status of the
function (see Section 13.2 on page 126). Any outputs marshalled
to these events will remain actuated for as long as the binary input
remains actuated.
>BU BLOCK
>BU BLKTrip
2303
2304
I
I
S
S
Event 2306 temporarily turns off just the 50HS function, while
event 2307 temporarily turns off just the 50/51 function.
>BU50HS BLK
>BU50/51 BLK
2306
2307
C
C
G
G
I
I
S
S
Pickup and Dropout
If any overcurrent function (50, 51, or 50HS) picks up, event 2411C
will occur. If no fault log is already open, a new one will open. The
pickup will dropout (event 2411G) when no overcurrent element
remains in pickup. Events 2412, 2413, and 2414 occur when each
phase picks up or drops out. Event 2421 occurs if the 50HS
function picks up, while event 2422 occurs if the 50/51 function
picks up.
Back Gen. Flt
BU Flt PhA
BU Flt PhB
BU Flt PhC
BU 50HS
BU 50/51
2411
2412
2413
2414
2421
2422
C
C
C
C
C
C
G
G
G
G
S
S
S
S
S
S
T
Time Delay Before Trip
If an overcurrent function picks up, the corresponding
time
-
before
-
trip delay starts. If the delay (addresses 2104, 2113, or
2115) is zero, these events do not occur.
BU Tdly 50HS
BU Tdly 50/51
2441
2442
C
C
S
S
T
T
Trip and Reset
The backup overcurrent element will trip if and when ANY of the
overcurrent elements (50, 51, or 50HS) has picked up and after the
corresponding time delay has not yet dropped out or already
caused a trip.
With the default marshalling a time overcurrent trip will light and
latch LED 4 and activate signal contact 3; and (as for a trip of any
element) light and latch LED 1, activate signal contact 1, and
activate all the trip contacts.
The overcurrent elements will reset (event 2411G, the same as for
dropout) when the same conditions that would cause a dropout
occur, and the reset time delay (Address 2118) expires.
BU Gen.Trip 2451 C S T
Configuration Error
The overcurrent elements are set to monitor Side 3
(Address 7821), but the protected object type (Address 7801) does
not have three sides (7UT513 only).
BU Err W3 2457 C S