2 Functions
126
7UM61 Manual
C53000-G1176-C127-3
vector. The value to be set must be established in accordance with the particular
power system. This can be done on the basis of the simplified equivalent circuit of the
diagram “voltage vector after a load shedding” in Section 2.20, or using network cal-
culation software.
If a setting is too sensitive, the protection function is likely to perform a network decou-
pling every time loads are connected or disconnected. Therefore the default setting is
10 °.
The admissible voltage operating range can be set at addresses 4605 for U MIN and
4606 for U MAX. Setting range limits are to some extent a matter of the utility's policy.
The value for U MIN should be below the admissible level of short voltage dips for
which network decoupling is desired. The default setting is 80% of rated voltage. For
U MAX the maximum admissible voltage must be selected. This will be in most cases
a voltage of 130% of rated voltage.
Time Delays The time delay T DELTA PHI (address 4603) should be left at zero, unless you wish
to transmit the trip indication with a delay to a logic (CFC), or to leave enough time for
an external blocking to take effect.
After expiry of the timer T RESET (address 4604), the protection function is automat-
ically reset. The reset time depends on the decoupling policy. It must have expired
before the circuit breaker is reclosed. Where the automatic reset function is not used,
the timer is set to ∞. The reset signal must come in this case from the binary input (cir-
cuit breaker auxiliary contact).
The timer T BLOCK with reset delay (address 4607) helps to avoid overfunctioning
when voltages are connected or disconnected. Normally the default setting need not
be changed. Any change can be performed with the DIGSI communication software
(advanced parameters). It must be kept in mind that T BLOCK should always be set
to more than the measuring window for vector jump measurement (2 cycles).
2.20.3 Settings
Addresses which have an appended "A" can only be changed with DIGSI, under Ad-
ditional Settings.
Addr. Parameter Setting Options Default Setting Comments
4601 VECTOR JUMP OFF
ON
Block relay
OFF Jump of Voltage Vector
4602 DELTA PHI 2 .. 30 ° 10 ° Jump of Phasor DELTA PHI
4603 T DELTA PHI 0.00 .. 60.00 sec; ∞ 0.00 sec T DELTA PHI Time Delay
4604 T RESET 0.10 .. 60.00 sec; ∞ 5.00 sec Reset Time after Trip
4605A U MIN 10.0 .. 125.0 V 80.0 V Minimal Operation Voltage U MIN
4606A U MAX 10.0 .. 170.0 V 130.0 V Maximal Operation Voltage U
MAX
4607A T BLOCK 0.00 .. 60.00 sec; ∞ 0.10 sec Time Delay of Blocking
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