Logic Of The Function; Application And Setting Notes - Siemens Reyrolle 7SR5 Manual

Protection and Automation Functions
5.10 49 Thermal Overload Protection

Logic of the Function

5.10.3
[lo_7SR5_49logicdiagram, 1, en_US]
Figure 5-13
5.10.4

Application and Setting Notes

The thermal state is calculated using the measured True RMS current.
Operate Time (T):
[fo_7SR5_thermal equation, 1, en_US]
T = Operate time in minutes
τ = Time constant (minutes)
In = Log natural
I = Measured current
I = Pre-load
p
I = Overload setting
θ
For the heating curve:
[fo_7SR5_heatingCurve, 1, en_US]
200
Logic Diagram: 49 Thermal Overload Protection
Reyrolle 7SR5, Transformer Protection Device, Device Manual
C53000-G7040-C015-1, Edition 11.2019