Derating
Derating for ambient temperature
The ambient temperature (T
AMB,MAX
) is the maximum
temperature allowed. The average (T
AMB,AVG
) meas-
ured over 24 hours must be at least 5C lower.
If the frequency converter is operated at temperatures
above 45C, a derating of the continuous output current
is necessary.
•
The current of VLT 5122-5552, 380-500 V
and VLT 5042-5352, 525-690 V, is to be de-
rated 1% / C above 45C maximum (160%
overload) and 40C maximum (110% over-
load). Max. temperature is 55° C.
•
The current of VLT 5402-5602, 525-690 V,
is to be derated 1.5% / C above 45C max-
imum (160% overload) and 40C maximum
(110% overload). Max. temperature is 55°
C.
Derating for Air Pressure
The Protective Extra Low Voltage (PELV)
requirements stated in IEC 61800-5-1 are
not fulfilled at altitudes above 2000 m
(6562 ft.). For 200V frequency converters
the requirements are not fulfilled at alti-
tudes above 5000 m (16 404 ft.). Please
contact Danfoss Drives for further infor-
mation.
Below 1000 m altitude no derating is necessary.
Above 1000 m the ambient temperature (T
AMB
) or max.
output current (I
VLT,MAX
) must be derated in accord-
ance with the diagram below:
1.
Derating of output current versus altitude at
T
AMB
= max. 45°C
2.
Derating of max. T
AMB
versus altitude at
100% output current.
VLT
®
5000 Design Guide
114
MG.52.B2.02 - VLT
®
is a registered Danfoss trademark
