Automatic Derating - Danfoss VLT AutomationDrive FC 300 Design Manual

Selection
Frame
model
D-frame
N55K to N315
525-690 V
4 4
E & F-frame
P355 to P1M0
525-690 V
Table 4.21 Derating Tables for Frequency Converters Rated 525-690 V (T7)

4.7.3 Automatic Derating

The frequency converter constantly checks for critical levels:
•
Critical high temperature on the control card or heatsink
•
High motor load or low motor speed
•
High DC link voltage
As a response to a critical level, the frequency converter adjusts the switching frequency. For critical high internal temper-
atures and low motor speed, the frequency converters can also force the PWM pattern to SFAVM.
NOTICE
The automatic derating is different when 14-55 Output Filter is set to [2] Sine-Wave Filter Fixed.
78
Switching
High overload HO, 150%
pattern
60 AVM
110
100
90
80
70
60
0 1 2
SFAVM
110
100
90
80
70
60
0 1
60 AVM
110
100
90
80
70
60
0.0 0.5 1.0 1.5 2.0
SFAVM
110
100
90
80
70
60
0.0 0.5 1.0
®
VLT AutomationDrive FC 300 Design Guide 90-1200 kW
o
50 C
o
55 C
3 4 4 5 5 6 7
o
45 C
o
50 C
o
55 C
2 3 4 5
o
50 C
55 C o
2.5 3.0 3.5 4.0 4.5 5.0 5.5
o
45 C
o
50 C
o
55 C
1.5 2.0 2.5 3.0 3.5 4.0
MG34S202 - Rev. 2013-08-19
Normal overload NO, 110%
110
100
90
80
70
60
50
0 1 2 3 4 5 5
110
100
90
80
70
60
50
0 1 2 3
110
100
90
80
70
60
50
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
110
100
90
80
70
60
50
0.0 0.5 1.0 1.5 2.0 2.5
o
45 C
o
50 C
o
55 C
6 7
o
40 C
o
45 C
o
50 C
o
55 C
4 5
o
45 C
o
50 C
o
55 C
4.5 5.0 5.5
o
40 C
45 C o
o
50 C
o
55 C
3.0 3.5 4.0