VLT ® 2900 Series A higher switching frequency (to be set in parameter 411, Switching frequency ) leads to higher losses in the electronics of the frequency converter. Derating for high switching frequency - VLT 2900 VLT 2900 has a pulse pattern in which it is possible to set the switching frequency from 3.0- 10.0/14.0 kHz. The frequency converter will automatically derate the rated output current I VLT,N, when the switching frequen- cy exceeds 4.5 kHz. In both cases, the reduction is carried out linearly, down to 60% of I VLT,N . When using the LC filter the minimum switch frequen- cy is 4.5 kHz.
Temperature-dependent switch frequency This function ensures the highest possible switch fre- quency without the frequency converter becoming thermally overloaded. The internal temperature is the actual expression of the degree to which the switch frequency can be based on the load, the ambient tem- perature, the supply voltage and the cable length. The function ensures that the frequency converter au- tomatically adjusts the switch frequency between f sw, min and f sw, max (parameter 411), see drawing below. All about VLT 2900 MG.29.A3.02 - VLT ® is a registered Danfoss trademark 77