Siemens SIPROTEC 4, User Manual

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pickup, will be signaled. If the 50-2 element or the 50-3 element is not required at all, the pickup threshold
50-2 or 50-3 is set to ∞. This setting prevents tripping and the generation of a pickup message.
High-set Current Elements 50N-2, 50N-3 (ground)
The pickup current of the high-set element
50N-2 PICKUP
or
50N-3 PICKUP
can be set at address 1302 or
1317. The corresponding delay time
50N-2 DELAY
or
50N-3 DELAY
can be configured under address 1303
or 1318. The same considerations apply to these settings as they did for phase currents discussed earlier.
The selected time is an additional delay time and does not include the operating time (measuring time,
dropout time). The delay can also be set to ∞. In this case, the element will not trip after pickup. However,
pickup, will be signaled. If the 50N-2 element or 50N-3 element is not required at all, the pickup threshold
50N-2 or 50N-3 should be set to ∞. This setting prevents tripping and the generation of a pickup message.
50-1 Element (phases)
For setting the 50-1 element, it is the maximum anticipated load current that must be considered above all.
Pickup due to overload should never occur since in this mode the device operates as fault protection with
correspondingly short tripping times and not as overload protection. For this reason, a setting equal to 20% of
the expected peak load is recommended for line protection, and a setting equal to 40% is recommended for
transformers and motors.
The settable time delay (address 1205
50-1 DELAY
) results from the grading coordination chart defined for
the system.
The selected time is an additional delay time and does not include the operating time (measuring time,
dropout time). The delay can also be set to ∞. In this case, the element will not trip after pickup. However,
pickup, will be signaled. If the 50-1 element is not required at all, then the pickup threshold 50-1 should be set
to ∞. This setting prevents tripping and the generation of a pickup message.
50N-1 Element (ground)
The 50N-1 element is normally set based on minimum ground fault current.
If the relay is used to protect transformers or motors with large inrush currents, the inrush restraint feature of
7SJ62/64 may be used for the 50N–1 relay element. It can be enabled or disabled for both the phase current
and the ground current in address 2201
INRUSH REST.
. The characteristic values of the inrush restraint are
listed in Subsection "Inrush Restraint".
The settable delay time (address 1305
50N-1 DELAY
) results from the time coordination chart defined for the
system. For ground currents in a grounded system a separate coordination timer with short time delays can be
applied.
The selected time is an additional delay time and does not include the operating time (measuring time,
dropout time). The delay can also be set to ∞. In this case, the element will not trip after pickup. However,
pickup, will be signaled. If the 50N-1 element is not required at all, the pickup threshold 50N-1 PICKUP should
be set to ∞. This setting prevents tripping and the generation of a pickup message.
Pickup Stabilization (Definite Time)
The configurable dropout times 1215
50 T DROP-OUT
or 1315
50N T DROP-OUT
can be set to implement a
uniform dropout behavior when using electromechanical relays. This is necessary for a time grading. The
dropout time of the electromechanical relay must be known to this end. Subtract the dropout time of the
device (see Technical Data) from this value and enter the result in the parameters.
51 Element (phases) with IEC or ANSI characteristics
Having set address 112
Charac. Phase
=
TOC IEC
or
TOC ANSI
when configuring the protection func-
tions (Section 2.1.1.2 Setting Notes ), the parameters for the inverse time characteristics will also be available.
If address 112
Charac. Phase
was set to
TOC IEC
, you can select the desired IEC characteristic (
Normal
Inverse
,
Very Inverse
,
Extremely Inv.
or
Long Inverse
) at address 1211
51 IEC CURVE
. If
address 112
Charac. Phase
was set to
TOC ANSI
, you can select the desired ANSI characteristic (
Very
Inverse
,
Inverse
,
Short Inverse
,
Long Inverse
,
Moderately Inv.
,
Extremely Inv.
or
Defi-
nite Inv.
) at address 1212
51 ANSI CURVE
.
Functions
2.2 Overcurrent Protection 50, 51, 50N, 51N
SIPROTEC 4, 7SJ62/64, Manual 75
C53000-G1140-C207-8, Edition 08.2016