Danfoss VLT Midi Drive FC 280

0%
0 2 4 6 8 10 12 14 16
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
K4 Derating Curve
Switching Frequency [kHz]
Output Current
45C
50C
55C
130BE892.10
Illustration 7.6 K4 Derating Curve
0%
0 2 4 6 8 10 12 14 16
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
K5 Derating Curve
Switching Frequency [kHz]
Output Current
45C
50C
55C
130BE893.10
Illustration 7.7 K5 Derating Curve
7.12.2 Automatic Derating
The frequency converter constantly checks for critical
levels:
•
Critical high temperature on the heat sink.
•
High motor load.
•
Low motor speed.
•
Protection signals (overvoltage/undervoltage,
overcurrent, ground fault, and short circuit) are
triggered.
As a response to a critical level, the frequency converter
adjusts the switching frequency.
Specications Design Guide
MG07B102 Danfoss A/S © 03/2016 All rights reserved. 85
7 7