Special Conditions; Manual Derating - Danfoss VLT AutomationDrive FC 300 Design Manual

Selection
Power size
125–175 hp [90–132 kW]/
525–690 V
225–425 hp
[160–315 kW]/
525–690 V
4 4
Table 4.18 dU/dt D-frame 525–690 V
1) With Danfoss dU/dt filter
Power size
475–1600 hp
[355–1200 kW]/525–690 V
Table 4.19 dU/dt E- and F-frames 525–690 V
1)
With Danfoss dU/dt filter.

4.7 Special Conditions

This section provides detailed data regarding the operating of the adjustable frequency drive in conditions that require
derating. In some conditions, derating must be done manually. In other conditions, the adjustable frequency drive performs
a degree of automatic derating when necessary. This is done to ensure proper performance at critical stages where the
alternative could be a trip.

4.7.1 Manual Derating

Manual derating must be considered for:
•
Air pressure – relevant for installation at altitudes above 3300 ft [1 km]
•
Motor speed – at continuous operation at low RPM in constant torque applications
•
Ambient temperature – relevant for ambient temperatures above 122 °F [50 °C]
86
Design Guide
Cable length AC line voltage
[m] [V]
150 690
150 1)
690
Cable length AC line voltage
[m] [V]
30 690
30 575
30 1)
690
Danfoss A/S © Rev. 2014-02-10 All rights reserved.
Rise time Peak voltage
[V]
[µs]
0.36 2135
0.46 2210
Rise time Peak voltage
[µs] [V]
0.57 1611
0.25
1.13 1629
dU/dt
[V/µs]
2.197
1.744
dU/dt
[V/µs]
2261
2510
1150
MG34S222