Siemens SIPROTEC 7SJ62 Instruction Manual

Functions
6-877SJ62 Manual
C53000-G1140-C121-1
Figure 6-40 Definite Time Characteristic for Negative Sequence Protection
6.7.1.3 Inverse Time Element (46-TOC)
The inverse time element is designated 46-TOC and can operate with IEC or ANSI
characteristic tripping curves depending on the model ordered. The curves and asso-
ciated formulas are given in the Technical Specifications (Figures 10-4 and 10-5 in
Section 10.8). When programming the inverse time curve, the definite time elements
are available (see Subsection 6.7.1.2).
Pickup and
Tripping
When the negative sequence current exceeds the pickup setting of the 46-TOC ele-
ment by 110%, the element picks up, generates a message, and initiates time delayed
tripping based on the selected characteristic curve. Once the corresponding time in-
terval on the curve elapses, a tripping signal is initiated. The characteristic curve is il-
lustrated in Figure 6-41.
Drop Out for IEC
Curves
When IEC curves are used, the 46-TOC element drops out when the negative se-
quence current decreases to 95 % of the pickup setting. The time delay resets imme-
diately in anticipation of another pickup.
Drop Out for ANSI
Curves
When ANSI curves are used, the 46-TOC element may drop out immediately when
the negative sequence current decreases to 95 % of the pickup setting, or disk emu-
lation may be used to simulate the unwinding of an electromechanical induction disc.
If disk emulation is selected, the drop out begins when the current decreases to 90 %
of the pickup value, and reset proceeds in accordance with the selected reset curve.
When the negative sequence current is between 90 % and 95 % of the pickup setting,
neither forward nor reverse movement of the disk is simulated. When the negative se-
quence current falls below 5 % of the pickup value, disk emulation is terminated and
immediate reset takes place. Figure 6-41 illustrates the overall tripping characteristic.
t
TI
2
>
TI
2
>>
I
2
>I
2
>> I
2
Auslösebereich
Tripping Area
46-1
46-2
46-1
46-2
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Siemens SIPROTEC 7SJ62 Specifications

General

Brand	Siemens
Model	SIPROTEC 7SJ62
Category	Relays
Language	English