Figure 4-3 Variable Pickup Under Current Graph - Siemens SINAMICS PERFECT HARMONY GH180 Function Manual

The resulting speed demand dependent pickup levels as shown in the figure titled "
Pickup Undercurrent Graph " shown below.
Variable Pickup Undercurrent
80
70
60
50
Undercurrent
Pickup Level 40
(%)
30
20
10
0
0
Figure 4-3 Variable Pickup Under Current Graph
Thermal Overload
The thermal overload protection functions use a thermodynamic model of the machine to
predict the total amount of thermal capacity (basically margin to maximum temperature) that
has been used as the machine temperature increases. A value of 100% thermal capacity used
would imply that the machine is at the maximum allowable temperature. The thermal model
uses a k-factor to adjust the value of current at which the machine will eventually reach full rated
Advanced Motor Protection for Variable Speed Operation
Manual, AA, A5E46373908A
Speed Demand (%)
30
40
50
60
70
70
90
100
110
120
130
140
150
160
170
180
190
50 100 150
Speed Demand
Advanced Motor Protection Parameters
4.1 Standard Protections Block Diagram
Undercurrent Pickup Level (%)
200 250
(%)
10
20
30
40
50
55
60
75
75
75
75
75
75
75
75
75
60
Variable
21