Danfoss FC 300 Design Manual

Also see for FC 300: Operating instructions Instruction manual Design guide Design guide Design guide

Contents

Danfoss FC 300 Design Manual Manual pdf 58 page image

EMC standards, Emission EN 61800-3, EN 61000-6-3/4, EN 55011EMC standards, ImmunityEN 61800-3, EN 61000-6-1/2,EN 61000-4-2, EN 61000-4-3, EN 61000-4-4, EN 61000-4-5, EN 61000-4-6See section on special conditionsControl card, USB serial communication :USB standard 1.1 (Full speed)USB plug USB type B ìdeviceî plugConnection to PC is carried out via a standard host/device USB cable.The USB connection is galvanically isolated from the supply voltage (PELV) and other high-voltage ter-minals.The USB ground connection is not galvanically isolated from protection earth. Use only isolated laptopas PC connection to the USB connector on FC 300 drive.EfficiencyEfficiency of FC 300 Series (η VLT)The load on the frequency converter has little effect on its efficiency. In general, the efficiency is the sameat the rated motor frequency fM,N , even if the motor supplies 100% of the rated shaft torque or only 75%,i.e. in case of part loads.This also means that the efficiency of the frequency converter does not change even if other U/f char-acteristics are chosen.However, the U/f characteristics influence the efficiency of the motor.The efficiency declines a little when the switching frequency is set to a value of above 5 kHz. The efficiencywill also be slightly reduced if the mains voltage is 500 V, or if the motor cable is longer than 30 m.Efficiency of the motor (ηMOTOR )The efficiency of a motor connected to the frequency converter depends on magnetising level. In general,the efficiency is just as good as with mains operation. The efficiency of the motor depends on the typeof motor.In the range of 75-100% of the rated torque, the efficiency of the motor is practically constant, bothwhen it is controlled by the frequency converter and when it runs directly on mains.In small motors, the influence from the U/f characteristic on efficiency is marginal. However, in motorsfrom 11 kW and up, the advantages are significant.In general, the switching frequency does not affect the efficiency of small motors. Motors from 11 kWand up have their efficiency improved (1-2%). This is because the sine shape of the motor current isalmost perfect at high switching frequency.Efficiency of the SYSTEM (ηSYSTEM )To calculate the SYSTEM efficiency, the efficiency of FC 300 Series (ηVLT ) is multiplied by the efficiencyof the motor (ηMOTOR ):ηSYSTEM) = η VLT x ηMOTORCalculate the efficiency of the SYSTEM at different loads based on the graph above.Acoustic NoiseThe acoustic noise from the frequency converter comes from three sources:1. DC intermediate circuit coils.2. Integral fan.3. RFI filter choke.FC 300 Design GuideFC 300 Selection58 MG.33.B7.02 - VLT is a registered Danfoss trademark