Danfoss VLT AQUA Drive FC 202 Operating Instructions Manual

Also see for VLT AQUA Drive FC 202: Service guide Installation guide Installation guide Operating guide Installation guide

Contents

4.1.2 GroundingTo obtain electromagnetic compatibility (EMC), considerthe following basic issues when installing a frequencyconverter.• Safety grounding: The frequency converter has ahigh leakage current (> 3.5 mA) and must begrounded appropriately for safety reasons. Applylocal safety regulations.• High-frequency grounding: Keep the ground wireconnections as short as possible.Connect the different ground systems at the lowestpossible conductor impedance. This is obtained by keepingthe conductor as short as possible and by using thegreatest possible surface area.The metal cabinets of the different devices are mountedon the cabinet rear plate using the lowest possible High-frequency impedance. This avoids having different High-frequency voltages for the individual devices and avoidsthe risk of radio interference currents running in anyconnection cables used between the devices. The radiointerference has been reduced.To obtain a low High-frequency impedance, use thefastening bolts of the devices as High-frequencyconnection to the rear plate. Remove any insulating paintor similar from the fastening points.4.1.3 Extra Protection (RCD)If local safety regulations are complied with, ELCB relays,multiple protective earthing or grounding can be used asextra protection.A ground fault may cause a DC component to develop inthe fault current.If ELCB relays are used, observe local regulations. Relaysmust be suitable for the protection of 3-phase equipmentwith a bridge rectifier and for a brief discharge on power-up.See also Special Conditions in the product relevant designguide.4.1.4 RFI SwitchMains supply isolated from groundTurn off (OFF)1) the RFI switch via 14-50 RFI Filter on thefrequency converter and 14-50 RFI Filter on the filter if:• The frequency converter is supplied from anisolated mains source (IT mains, floating delta andgrounded delta).• The frequency converter is supplied from TT/TN-Smains with grounded leg.For further reference, see IEC 364-3.Set 14-50 RFI Filter to [ON] if:• Optimum EMC performance is needed.• Parallel motors are connected.• The motor cable length is above 25 m.1) Not available for 525-600/690 V frequency converters.In OFF, the internal RFI capacities (filter capacitors)between the chassis and the intermediate circuit are cutoff to avoid damage to the intermediate circuit and toreduce the ground capacity currents (according to IEC61800-3).Also refer to the application note VLT on IT mains. It isimportant to use isolation monitors which are compatiblewith power electronics (IEC 61557-8).4.1.5 TorqueWhen tightening all electrical connections, it is importantto tighten with the correct torque. Too low or too hightorque results in a poor electrical connection. Use a torquewrench to ensure correct torque.176FA247.12Nm/in-lbs-DC 88 +DC 89R/L1 91 S/L2 92 T/L3 93U/T1 96 V/T2 97W/T3Illustration 4.12 Tightening Torques.Enclosure size Terminal Torque Bolt sizeF8-F14 MainsMotor19-40 Nm(168-354 in-lbs)M10BrakeRegen8.5-20.5 Nm(75-181 in-lbs) M8Table 4.2 Tightening TorquesHow to Install Operating InstructionsMG20Y202 Danfoss A/S © Rev. 06/2014 All rights reserved. 354 4