Special Conditions; Purpose Of Derating - Danfoss VLT AQUA Drive Design Manual

3. VLT AQUA Selection
FC 202, P30KT2
Cable
length [m]
15
50
150
3
FC 202, P30KT2
Cable
length [m]
15
50
150
FC 202, P90KT5
Cable
length [m]
5
5

3.5. Special Conditions

3.5.1. Purpose of derating

Derating must be taken into account when using the adjustable frequency drive at low air pressure
(high elevations), at low speeds, with long motor cables, cables with a large cross-section or at
high ambient temperature. The required action is described in this section.
3.5.2. Derating for Ambient Temperature
The average temperature (T
than the maximum allowed ambient temperature (T
If the adjustable frequency drive is operated at high ambient temperatures, the continuous output
current should be decreased.
The derating depends on the switching pattern, which can be set to 60 PWM or SFAVM in pa-
rameter 14-00.
60
AC line Rise time
voltage [μsec]
240 V 0.194
240 V 0.252
240 V 0.488
AC line Rise time
voltage [μsec]
240 V 0.117
240 V 0.150
240 V 0.184
AC line Rise time
voltage [μsec]
400 V 0.240
480 V 0.184
) measured over 24 hours must be at least 9° F [5° C] lower
AMB, AVG
MG.20.N2.22 - VLT ® is a registered Danfoss trademark.
VLT ®
Vpeak dU/dt
[kV] [kV/μsec]
0.626 2.581
0.574 1.822
0.538 0.882
Vpeak dU/dt
[kV] [kV/μsec]
0.626 2.410
0.574 1.531
0.538 1.170
Vpeak dU/dt
[kV] [kV/μsec]
1.030 1.683
1.170 2.652
).
AMB,MAX
AQUA Drive Design Guide