NHP TemBreak PRO P - I 2 T Function for STD

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