Protection - Inrush Inhibit - ABB Eagle Programming Manual

Parameter Range
Pickup value 10...7500
Curve As per the
user defined
Curves
t 0.00... 64.00
Block
NO
YES
Block during
NO
Inrush
YES
CLP apply
NO
YES
K 0.02...1.6
TDmin 0.0...0.25

4.4.2. Protection - Inrush Inhibit

Inrush detection is used to coordinate transformer inrush situations. Inrush detection
selectively blocks overcurrent function when the ratio of second harmonic component
over the fundamental component exceeds the set value.
Inrush current is a ratio of second harmonic current (I2) to the fundamental frequency
current (I1) value. Inrush logic detects inrush conditions and blocks the over current
protection functions if following conditions are satisfied.
a) Fundamental current should be greater than 10% of rated current and less than I inr
max current setting.
b) Inrush current I2/I1 should be greater than Inrush ratio setting.
The blocking remains activated as long as these conditions are satisfied. For overcurrent
function to be blocked by inrush it is required that setting Blocked by inrush is set as
"Yes" in respective over current protection function.
Once inrush detect output is activated and inrush condition mentioned in conditions a or
b remain failed for a time of 30ms, the Inrush blocking is deactivated.
Table 5 Inrush protection User settings
Parameter Range
Inrush 10 ... 50
ratio
Unit Step
A 1
- 1
s 0.01
- 1
- 1
- 1
- 0.01
s 0.01
Unit Step Default
- 1 30
Default Description
250 Pickup value
Definite Curve Types
Time
0.50 Trip delay time
No Block the function
Yes Blocking by Inrush Status
Yes Cold load pickup condition
application to function
0.5 Curve Parameter
0.00 Min trip delay time for IDMT
curve
Description
Inrush ratio leading to inrush detection.
23