NHP TemBreak PRO P, User Manual

Page: 32 / 66

Protection Settings
Short Time Delay Protection (STD)
32
TemBreak PRO
P_BE-UM-001-EN V1.3.0
I
2
t function for STD
When enabled, the I²t function for STD may be used to improve selectivity with downstream devices by overlaying a supplementary I
2 t = K curve within the
STD tripping section, starting from the I
sd
threshold setting up to the I
i
threshold setting.
The below graphic illustrates the difference between I
2
t enabled and disabled with a I
2
t curve based on I
r
= 630A for reference.
Settings Full curve
without I
2
t enabled
Full curve
with I
2
t enabled
I 2 t ONLY
base on I
r
=630A
I
r
630A 630A 630A
t
r
5s 5s 5s
I
sd
5 5 1.5
t
sd
50ms 50ms 50ms
I
i
9 9 11
I 2 t Disabled Enabled Enabled