Siemens siprotec SJ62 User Manual page 79

2 Functions
Pickup Stabilization
(Definite Time)
51 Element with IEC
or ANSI Character-
istics
51N Element with
IEC or ANSI Char-
acteristics
77
The dropout times 1215 50 T DROP-OUT or 1315 50N T DROP-OUT can be set to
implement a uniform dropout behaviour 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 7SJ relay (see Technical Data) from
this value and enter the result in the parameters.
Having set address 112 Charac. Phase = TOC IEC or TOC ANSI when configuring
the protective functions (Section 2.1.1.2), the parameters for the inverse characteristic
will also be available.
If address 112 Charac. Phase = TOC IEC, you can specify the desired IEC–
characteristic (Normal Inverse, Very Inverse, Extremely Inv. or Long
Inverse) in address 1211 51 IEC CURVE. If address 112 Charac. Phase = TOC
ANSI, you can specify the desired ANSI–characteristic (Very Inverse, Inverse,
Short Inverse, Long Inverse, Moderately Inv., Extremely Inv. or
Definite Inv.) in address 1212 51 ANSI CURVE.
If the inverse time trip characteristic is selected, it must be noted that a safety factor
of about 1.1 has already been included between the pickup value and the setting
value. This means that a pickup will only occur if a current of about 1.1 times the
setting value is present. If Disk Emulation was selected at address 1210 51
Drop-out, reset will occur in accordance with the reset curve as described before.
The current value is set at address 1207 51 PICKUP. The setting is mainly deter-
mined by the maximum operating current. Pickup due to overload should never occur,
since the device, in this mode, operates as fault protection with correspondingly short
tripping times and not as overload protection.
The corresponding element time multiplication factor for an IEC characteristic is set at
address 1208 51 TIME DIAL and in address 1209 51 TIME DIAL for an ANSI
characteristic. It must be coordinated with the time grading of the network.
The time multiplier can also be set to ∞. After pickup the element will then not trip.
Pickup, however, will be signaled. If the 51 element is not required at all, address 112
Charac. Phase should be set to Definite Time during protective function con-
figuration (see Section 2.1.1.2).
Having set address 113 Charac. Ground = TOC IEC when configuring the protec-
tive functions (Section 2.1.1), the parameters for the inverse characteristics will also
be available. Specify in address 1311 51N IEC CURVE the desired IEC characteristic
(Normal Inverse, Very Inverse, Extremely Inv. or Long Inverse). If
address 113 Charac. Ground = TOC ANSI, you can specify the desired ANSI–
characteristic (Very Inverse, Inverse, Short Inverse, Long Inverse,
Moderately Inv., Extremely Inv. or Definite Inv.) in address 1312 51N
ANSI CURVE.
If the inverse time trip characteristic is selected, it must be noted that a safety factor
of about 1.1 has already been included between the pickup value and the setting
value. This means that a pickup will only occur if a current of about 1.1 times the
setting value is present. If Disk Emulation was selected at address 1310 51
Drop-out, reset will occur in accordance with the reset curve as described before.
The current value is set at address 1307 51N PICKUP. The most relevant for this
setting is the minimum appearing ground fault current.
The corresponding element time multiplication factor for an IEC characteristic is set at
address 1308 51N TIME DIAL and in address 1309 51N TIME DIAL for an ANSI
characteristic. This has to be coordinated with the grading coordination chart of the
SIPROTEC 4, 7SJ62/63/64 Handbuch
C53000-G1140-C147-A, Edition 07.2015