Function 51 I4T Pickup And Reset - Siemens SINAMICS PERFECT HARMONY GH180 Function Manual

Figure 6-58
6.18.7

Function 51 I4T Pickup and Reset

Pickup and Reset Curve Equations and Tables
Pickup time as a function of current as well as the reset time are shown for I
below.
I t Curve
4
The pickup time as a function of current is given by:
T
pu
Figure 6-59
Advanced Motor Protection for Variable Speed Operation
Manual, AA, A5E46373908A
500
450
400
350
300
250
200
150
100
0 0.1 0.2
I2t Inverse Reset Time
 
 
100
=
TDM
 
4
 
I
 
rms
 
 
 
I
 
pu
I t Pickup Time equation
4
Advanced Motor Protection and RTD Protection Functions
6.18 Device 51 - Fixed Inverse Time Overcurrent
2
I t
inverse reset time
TDM=1.0
0.3 0.4
stator current to pickup current ratio
0.5 0.6 0.7
t curves as shown
4
0.8 0.9
121