Special Conditions; Manual Derating - Danfoss VLT Midi Drive FC 280 Design Manual

Specifications
Cable
length
[m (ft)]
5 (16.4)
50 (164)
Table 7.12 dU/dt Data for FC 280, 2.2 kW (3.0 hp), 3x200–240 V
Cable
length
[m (ft)]
5 (16.4)
50 (164)
Table 7.13 dU/dt Data for FC 280, 3.7 kW (5.0 hp), 3x200–240 V
Cable
length
7 7
[m (ft)]
5 (16.4)
50 (164)
Table 7.14 dU/dt Data for FC 280, 1.5 kW (2.0 hp), 1x200–240 V
Cable
length
[m (ft)]
5 (16.4)
50 (164)
Table 7.15 dU/dt Data for FC 280, 2.2 kW (3.0 hp), 1x200–240 V

7.12 Special Conditions

Under some special conditions, where the operation of the
frequency converter is challenged, consider derating. In
some conditions, derating must be done manually.
In other conditions, the frequency converter automatically
performs a degree of derating when necessary. Derating is
done to ensure the performance at critical stages where
the alternative could be a trip.

7.12.1 Manual Derating

Manual derating must be considered for:
•
Air pressure – for installation at altitudes above
1000 m (3281 ft).
•
Motor speed – at continuous operation at low
RPM in constant torque applications.
•
Ambient temperature – above 45 °C (113 °F), for
details, see Illustration 7.3, Illustration 7.4,
Illustration 7.5, Illustration 7.6, and Illustration 7.7.
84
Mains
Rise time
voltage U
PEAK
[V] [μsec] [kV]
240 0.072 0.468
240 0.208 0.592
Mains
voltage Rise time U
PEAK
[V] [μsec] [kV]
240 0.092 0.526
240 0.28 0.6
Mains
voltage Rise time U
PEAK
[V] [μsec] [kV]
240 0.088 0.414
240 0.196 0.593
Mains
voltage Rise time U
PEAK
[V] [μsec] [kV]
240 0.112 0.368
240 0.116 0.362
Danfoss A/S © 03/2016 All rights reserved.
®
VLT Midi Drive FC 280
dU/dt
100%
[kV/μsec]
90%
5.25
80%
2.28
70%
60%
50%
40%
30%
dU/dt
20%
[kV/μsec]
10%
4.56
0%
1.72
Illustration 7.3 K1 Derating Curve
dU/dt
[kV/μsec]
100%
3.79
90%
2.41
80%
70%
60%
50%
40%
dU/dt
30%
[kV/μsec]
20%
2.64
10%
2.51
0%
Illustration 7.4 K2 Derating Curve
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Illustration 7.5 K3 Derating Curve
K1 Derating Curve
0 2 4 6 8 10
Switching Frequency [kHz]
K2 Derating Curve
0 2 4 6 8 10
Switching Frequency [kHz]
K3 Derating Curve
0 2 4 6 8 10
Switching Frequency [kHz]
45C
50C
55C
12 14 16
45C
50C
55C
12 14 16
45C
50C
55C
12 14 16
MG07B102