Danfoss VLT AutomationDrive FC 300 Design Manual

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

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Danfoss VLT AutomationDrive FC 300 Design Manual Manual pdf 266 page image

9.11 Sine-wave FiltersWhen a motor is controlled by an adjustable frequencydrive, resonance noise is heard from the motor. This noise,which results from the motor design, arises every time aninverter switch in the adjustable frequency drive isactivated. The frequency of the resonance noise thuscorresponds to the switching frequency of the adjustablefrequency drive.For the FC 300, Danfoss can supply a sine-wave filter todampen the acoustic motor noise. The filter reduces theramp-up time of the voltage, the peak load voltage UPEAK,and the ripple current ΔI to the motor. This results in thecurrent and voltage becoming almost sinusoidal, whichreduces the acoustic motor noise.The ripple current in the sine-wave filter coils also causessome noise. This problem can be solved integrating thefilter in a cabinet or similar enclosure.9.12 High Power OptionsOrdering numbers for high power options can be found inchapter 5 How to Order.9.12.1 Frame Size D Options9.12.1.1 Load Share TerminalsLoad share terminals enable the connection of the DCcircuits of several adjustable frequency drives. Load shareterminals are available in IP20 adjustable frequency drivesand extend out the top of the unit. A terminal cover,supplied with the adjustable frequency drive, must beinstalled to maintain the IP20 rating of the enclosure.Figure 9.21 shows both the covered and uncoveredterminals.130BC547.10Figure 9.21 Load Share or Regeneration Terminal with Cover(Left) and without Cover (Right)9.12.1.2 Regeneration TerminalsRegen (regeneration) terminals can be supplied forapplications that have a regenerative load. A regenerativeunit, supplied by a third party, connects to the regenterminals so that power can be sent back onto line power,resulting in energy savings. Regen terminals are availablein IP20 adjustable frequency drives and extend out the topof the unit. A terminal cover, supplied with the adjustablefrequency drive, must be installed to maintain the IP20rating of the enclosure. Figure 9.21 shows both the coveredand uncovered terminals.9.12.1.3 Anti-condensation HeaterAn anti-condensation heater can be installed inside theadjustable frequency drive to prevent condensation fromforming inside the enclosure when the unit is turned off.The heater is controlled by customer-supplied 230 V AC.For best results, operate the heater only when the unit isnot running.A 2.5 amp time-delay fuse, such as the BussmannLPJ-21/2SP, is recommended to protect the heater.9.12.1.4 Brake ChopperA brake chopper can be supplied for applications thathave a regenerative load. The brake chopper connects to abrake resistor, which consumes the braking energy andprevents an overvoltage fault on the DC bus. The brakechopper is automatically activated when the DC busvoltage exceeds a specified level, depending on thenominal voltage of the adjustable frequency drive.9.12.1.5 Line Power ShieldThe line power shield is a Lexan cover installed inside theenclosure to provide protection according to VBG-4accident-prevention requirements.9.12.1.6 Ruggedized Printed Circuit BoardsRuggedized boards are available for marine and otherapplications that experience higher than average vibration.NOTICE!Ruggedized boards are required to meet marineapproval requirements.Options and Accessories Design Guide264 Danfoss A/S © Rev. 2014-02-10 All rights reserved. MG34S22299