Lenze DSD - Manual (Page 472)

18 Drive dimensioning messages
18.8 Inverters
472
Lenze · Drive Solution Designer · Manual · DMS 4.2 EN · 12/2013 · TD23
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18.8.25 Thermal utilisation of the inverter is > 80 %
Warning!
The thermal utilisation of the inverter is xxx.
A manual, thermal check of the inverter is required
in the case of longer or cyclic operating phases with field frequencies < 5 Hz and
an output current > rated current.
Cause Effects Possible remedies
The actual thermal utilisation (I×t) is
determined within the inverter, as a
function of the field frequency and
with different time constants.
The DSD model works with a simpli-
fied algorithm.
At field frequencies < 5 Hz and an
output current > rated current, the
actual utilisation may be slightly
higher than the utilisation deter-
mined by DSD.
• Provide for sufficient I×t reserves
by selecting a more powerful in-
verter.
• Detailed check of the thermal uti-
lisation.
• Contact Lenze Support.
• Determine thermal utilisation
in tests.