Siemens siprotec SJ62 User Manual page 97

2 Functions
User-defined
Curves
95
Disk emulation offers advantages when the overcurrent relay elements must be coor-
dinated with conventional electromechanical overcurrent relays located toward the
source.
When user-defined characteristic are utilized, the tripping curve may be defined point
by point. Up to 20 value pairs (current, time) may be entered. The device then approx-
imates the characteristic, using linear interpolation.
The dropout curve may be user-defined as well. This is advantageous when the over-
current protection must be coordinated with conventional electromechanical overcur-
rent relays located toward the source. If no user-specified dropout curve is required,
the element pickup drops out as soon as the measured signal is less than approx. 95%
of the pickup setting. When a new pickup is evoked, the timer starts at zero again.
SIPROTEC 4, 7SJ62/63/64 Handbuch
C53000-G1140-C147-A, Edition 07.2015