
177
[1.8 FAULT MANAGEMENT]
(FLt-)
Motor thermal protection
Function:
Thermal protection by calculating the I
2
t.
Note: The memory of the motor thermal state is saved when the drive is switched off. The power-off time is used to recalculate the
thermal state the next time the drive is switched on.
• Naturally-cooled motors:
The tripping curves depend on the motor frequency.
• Force-cooled motors:
Only the 50 Hz tripping curve needs to be considered, regardless of the motor frequency.
10 000
1 000
100
0,7
0,8
0,9
1
1,1
1,2
1,3
1,4
1,5
1,6
50 Hz
20 Hz
10 Hz
1 Hz 3 Hz 5 Hz
Trip time in seconds
Motor current/ItH
Summary of Contents for ER40-G
Page 2: ......
Page 21: ...21 The display flashes to indicate the presence of a fault ...
Page 241: ......