Settings For Phase Overcurrent Protection - Siemens SIPROTEC 7SJ62 Instruction Manual

Functions
6.2.2.2

Settings for Phase Overcurrent Protection

Addr. Setting Title
1201 FCT 50/51
6-32
The time and current value pairs are entered at address  to recreate the drop-
down curve. The following must be observed:
Reset Curve
t
Largest Current Point
Smallest Current Point
0.05
Figure 6-18 Use of a User-Specified Curve
− Current flows which are greater than the largest current value entered will not lead
to an extension of the reset time beyond the time associated with the largest current
value entered. The reset curve (see Figure 6-18) represents constant reset time for
currents larger than the largest current value entered.
− Current flows which are less than the smallest current value entered will not lead to
a reduction of the reset time below the time associated with the smallest current val-
ue entered. The reset curve (see Figure 6-18) represents constant reset time for
currents smaller than the smallest current value entered.
− Current flows less than 0.05 * 51 pickup setting will cause immediate reset.
In the list below, the setting ranges and default setting values for the pickup currents
are for a device with a nominal current rating I
= 1 A, divide the Setting Options values and Default Setting values by 5. Consider the
current transformer ratios when setting the device with primary values.
Setting Options Default Setting
ON ON
OFF
Characteristic Curve
Smallest Current Point
Largest Current Point
0.9 1 1.1
= 5 A. For a nominal current rating I
N
Comments
Time-overcurrent protection
enabling
I
20
N
Configuration
X X X X X
7SJ62 Manual
C53000-G1140-C121-1