WEG CFW900 - And Delta Corner Earthed Networks

English
INSTALLATIONANDCONNECTION
!
DANGER!
Provideadisconnectdeviceforthepowersupplyoftheinverter.Thisdevicemustdisconnectthe
powersupplywhenevernecessary(duringmaintenancejobs,forinstance).
!
WARNING!
AcontactororanotherdevicethatfrequentlydisconnectsandreappliestheACsupplytotheinverter,
inordertostartandstopthemotor,maycausedamagetotheinverterpowersection.Usecontrol
signalstostartandstopthemotor.Ifused,thedeviceintheinputcannotexceedoneoperationper
minuteortheinvertermaybedamaged.
✓
NOTE!
Thepowersupplyvoltageshallbecompatiblewiththeinverterratedvoltage.
Powerfactorcorrectioncapacitorsarenotneededattheinverterinput(R/L1,S/L2,T/L3)andshall
notbeinstalledattheoutputoftheinverter(U,V,W).
!
WARNING!
Residualcurrentdevice(RCD):
Whenusedintheinvertersupply,itmusthaveapick-upcurrentof300mA.
Dependingontheinstallation(motorcablelength,cabletype,multimotorconfiguration,etc.),the
RCDprotectionmaybeactivated.ContacttheRCDmanufacturerforselectingthemostappropriate
devicetobeusedwithinverters.
Considerthefollowingitemsfortheuseofprotectiondevicesonthesupplysideoftheinvertersuchasresidual
currentdevicesorisolationmonitors:
Thedetectionofaphase-to-groundshort-circuitoraninsulationfaultshallbeprocessedbytheuser,i.e.,the
usershalldecidewhethertoindicatethefaultand/orblocktheinverteroperationorboth.
ContacttheRCDmanufacturerforselectingthemostappropriatedevicetobeusedwithinvertersinorderto
avoidnuisancetrippingduetothehighfrequencyleakagecurrentsthatflowthroughtheleakagecapacitances
oftheinverter,cable,andmotorsystemtotheground.
3.2.4.1ITandDeltaCornerEarthedNetworks
!
WARNING!
TheinvertersoftheCFW900linecanoperateinpowersupplywithasolidlygroundedneutral,in
deltacornerearthednetworksandITnetworks(ungroundedneutralorgroundingbyahighohmic
valueresistor). Exception:invertersofframeAcannotoperateindeltacornerearthednetworks
andresistor-groundedITnetworks.
TooperateindeltacornerearthednetworksandITnetworks,itisnecessarytodisconnecttheRFI
filter.
Independentofthetypeofpowergrid,theinvertermustalwaysbeconnectedtoprotectiveground
accordingtothe
item3.2.5.
InvertersoftheCFW900seriescanbeusedinITnetworkswithgroundingmadebyresistors(exceptmodelsof
frameA).Tothatend,removethegroundingscrewsfromthefiltercapacitors,asshownin
Figure3.13.Toaccess
thesescrewsonframesA,B,CandD,removetheHMIandthefrontcover.InframeE,itisnecessarytoremove
thelowerfrontcover.
ItisalsopossibletooperatetheCFW900indeltacornerearthednetworks,exceptformodelsofframeA.Inthese
cases,thegroundingscrewsofthefiltercapacitorsmustalsoberemoved,asshownin
Figure3.13.
30|CFW900