Danfoss VLT AQUA Drive Design Manual page 62

3. VLT AQUA Selection
C enclosures
60 PWM (Pulse Width Modulation)
3
3.7: Derating of I
closure C, using 60 PWM in normal torque mode
(110% over-torque)
3.5.3. Derating for Low Air Pressure
The cooling capability of air is decreased at a lower air pressure.
At altitudes higher than 6,600 feet [2 km], please contact Danfoss Drives regarding PELV.
At an altitude lower than 3,280 ft [1,000 m], no derating is necessary; but at an altitude higher
than 3,280 ft [1,000 m], the ambient temperature (T
derated in accordance with the diagram shown.
3.9: Derating of output current versus altitude at T
contact Danfoss Drives regarding PELV.
An alternative is to lower the ambient temperature at high altitudes and thereby ensure 100%
output current at high altitudes.
62
for different T for en-
out AMB, MAX
MG.20.N2.22 - VLT ®
VLT
SFAVM - Stator Frequency Asyncron
Vector Modulation
3.8: Derating of I for different T
out
closure C, using SFAVM in normal torque mode
(110% over-torque)
) or max. output current (I
AMB
. At altitudes higher than 6,600 feet [2 km], please
AMB, MAX
is a registered Danfoss trademark.
® AQUA Drive Design Guide
for en-
AMB, MAX
) should be
out