Time Delays; Events And Actions - Siemens 7UT51 Instruction Manual

7UT51 v3
5.7

Time Delays

If an 87M/G pickup occurs, the 87M/G function will
immediately trip unless a corresponding time delay
has been set in Address 1725.
1725 87 DELAY
Time delay between pickup and trip for 87
differential protection (in addition to the
inherent operating time of the relay).
60.00 s, or ∞
–
Range: 0.00
Default: 0.00 s
To ensure that the trip state lasts long enough for the
circuit breaker to operate, the trip state can be
prolonged by a reset time delay that is set in
Address 1727.
-
1727 T RESET
Additional time to remain in trip state after the
87 function trip state disappears (in addition
to the inherent reset time of the relay).
–
Range: 0.00 60.00 s
Default: 0.10 s
Motor or Generator Differential Protection (87M/G) Occurrence
Change in Operational Status
When the operational status of the 87M/G function changes, a
-
going event for the old status occurs followed by a coming
for the new status. The normal operational status is set in
Address 1701.
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.
Pickup and Dropout
If the operating point of any phase rises above 85% of the setting
threshold of the pickup characteristic, or if the restraint current
(I ) exceeds four times rated nominal current (I
rest
function will pickup (event 5631C). If no fault log is already open, a
new one will open.
If the operating point for all phases remains below 70% of the
setting threshold of the pickup characteristic for two full cycles, the
87M/G function will dropout (event 5631G). See Section 5.4 on
page 71.
-
An 87M/G phase pickup occurs if the operating point of a phase
rises above the pickup characteristic. Outputs marshalled to these
events will remain actuated until dropout of the corresponding
phase.
PRIM-2330C
Motor or Generator Differential Protection (87M/G)
5.8
Table 5.1 describes the events that control and are
generated by the 87M/G function. 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").
LCD Abbreviation
87Diff OFF
87Diff BLOCK
-
event
87Diff ACTIVE
>87Diff BLOCK
>87DiffBlkTrip
87Diff GenFlt
), the 87M/G
n
87Diff PhA
87Diff PhB
87Diff PhC

Events and Actions

Event Oper
5615 C G
5616
C G
5617
C G
5603
5605
5631
5681
5682
5683
5
Fault In/Out
S
S
S
I S
I S
C G S T
C S
C S
C S
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