electrical and grounding review for temperature profiler · electrical and grounding review for...

ElectricalandGroundingReviewforTemperatureProfiler

JelenaMaricic.YujingSun,RadovanMilincic,CaryKendziora,StephenPordes

UniversityofHawaii&FermilabSeptember26th,2017

HawaiiTemperatureProfiler• Highprecisionrelativetemp.measurementachievedbymovablearray,allowingcross-referencingoftemperaturesensorsin-situ.

LakeshoreRTDtemperaturesensorPT-102

FragilesensorcarefullyfastenedtoPCB

2PCBswithsensorsattachedto1mlongsegmentswith0.5mspacingbetweenthem

Entirearrayis7.5mhigh,spanning thefullheightofprotoDUNE LAr volume

Temperatureprofilermovesusingsteppermotor thatmovestherackandpiniongearsystemconnectedtorodassemblyupto1m.

• Immunetochangesfromlabtestingtoinstallation.

• Measurementtakenintwoeasystepswithentirearraymoveduptocomparereadingsfromtwosensorsateachlocationforcross-referencing.

• Expecttoachieverequiredtemp.measurementprecisionoffewmK.

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Electricschemeoverviewforsensorconnections

SensorShieldedCablewithtwotwistedwirepairsSensor leadssoldered towires.Eachleadsolderedtotwowires.

D-sub25connectorOntheflange

FlangewithfeedthroughConnectors.Flangeisgrounded, butwiresareinsulatedfromtheground.

Tmonitor

GroundedToslowcontrolrack

Slowmonitoring e-rack.

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RTDsensorconnection• Systemislocatedbehindtheanodeplane• Fourwireconnectionforeachsensortoeliminatetheinfluenceofleadsandcontacts• Twotwistedpairsshieldedontheoutsidebyabraidedcable.• Sensorpinsandwireswillbesolderedoncommonpadsforconnection.• Sensorisheldinplacebytwowrap-aroundstainlesssteelloopstoprotectitfromvibrations.• TheFR4cutoutaroundthesensorallowsfreeflowofargon.

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RTDcableRestrainingSystem

• CableissandwichedbetweenthePCBandstainlesssteelrodmount.• Sensorsolderingjointsaretensionfreeduringconstructionandinstallation.

• Fourscrewsholdtogethertwoboardsandcableinbetween,tomakeasandwich.

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FR4withRTD

Cable

StainlesssteelplatetosandwichAndsecurethecableandConnectittocarrierrod.

Connectionscrew.

MountingtheRTDSensorFR4BoardtoCarrierRod

• RTDsensorFR4boardandtopstainlesssteelboardareattachedtothecarrierrodviastainlesskeythatrunsalongtheentirerodlength.• Itisattachedwithtwostainlesssteelscrews.

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StainlesskeytoattachsensorAssemblies.

Cablecomposition

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BraidedshieldisnotconnectedtotheflangeButfreelyfloats.

MotorandcarrierrodInstallationandOverview

• Carrierrodhasamechanicalstopatthetopthatpreventsthecarrierrodfromslippinginsidethecryostat.

Oncethecarrierrodisinplace,itisconnectedtothedriveassemblybeingloweredonthetopofit.

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Viewupthesleeve• ThesleevehasadoublesidedCFflange.

• Spiderguideislocatedatthebottomofthesleeve.

• Spiderguideholdingfirmlythecarrierrodtoavoidanylateralmotion.

• DistancebetweenAPAandtemperaturemonitorflange20cm.

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Detailsofthespiderguide

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Contactbetweenthespiderguideandsleeve

• Portandsleevearefullyincontactandconnectedtoground.

• Spiderguideisweldedtothesleeve.

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Teflonslidebearing

Theguidingsleeve• Sleevefitsinsidetheportandtheyareincontactalongtheentirelengthandconnectedtothegroundofthecryostat.• Spiderguidealsostainlesssteelandweldedtothebottomofthesleeve.

Spiderguide– insulatedfromtherod bydesign.

TeflonslidebearingthatismadeofonlyPTFE,toisolateelectricallyfromthespider.

Spiderguide isconnectedtothesleeve.SleeveisincontactwithaportandCryostatandtheyareallgrounded.

Sleeve

Port

Cryostat

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TheCarrierRodLocationwhereWherecarrierrodisconnectedtoground.

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Motorconnectiontoground

Motor isconnectedtotheground througharodatRackandpiniongearpointconnection.

Theenclosure isinsulatedfromthefloor, fromthemotorbodyandpipeenclosing thecarrierrod.

Theenclosureconnection totheground isthrough ferrofluidic sealandthehousing oftherackandpiniongear.

GreenrectanglesshowinsulationusingG10orFR4.

Ifnecessary,theenclosurecanbecompletelyinsulatedfromtheground.

Insulatedfromthefloor.

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Driveassemblyselection• CaryhasselectedasteppermotorfromTecmatic andisintheprocessofcheckingallthespecstofitourneeds.

• ItisaDCmotorusing<48V.• Largenumberofstepsforfinepositioning.• Usesdoublewormgearforexcellentspeedcontrol(~0.3cm/s)• Itcanbecompletelypoweredoffwhennotinuse• Itusesabsoluteencoder– remembersabsolutepositionafterbeingturnedoffandonagain.

• Utilizesamechanicalbreakthatstaysonwhenthepowerisoff.• Canslidethesystemupanddownmanuallyincaseofmotorfailure• Mechanicalstopatthetopoftheassemblyrod,preventstherodfromslippingdowninsidethecryostat

• Manualcontrolincaseofmotorfailure.

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FabricationandTestingPlan• Thetemperatureprofilerwillbefabricated,assembledandtestedinHawaiiandatFermilab.

ü ElectricconnectionsforallsensorswillbetestedaftersolderingpinsandwirestotheFR4boardbytakingtemperaturereadingsdirectlywithatemperaturemonitor.

ü SensorswillbeloweredinLN2alongwithacalibratedsensor.Temperaturereadingwillbetakenforbothsensorstotestwhethertheyareinagoodworkingconditionandforcrudecomparison.

ü Twistedpairsofwiresarecolorcodedandlabelswillbeplacedontheoutsideofthecablesonbothends,oncethesensorisattachedtocertainlocationonthecarrierrod.

ü LabelswilllooklikeRTD-1-750(themiddlenumberisthesensornumberbasedonlabtestingofthesensor,whilethelastnumberisthepositionofthesensoronthecarrierrod)

ü Carrierrodpieceswillbeassembledanddisassembled.

ü Driveassemblywillbetested,includingthemotorbreak,theencoder,manualdriveandoveralloperation.Thesystemwillbedrivenalargenumberoftimestocheckforslippageorothereffects.

ü Theentiresystemwillbeassembledandtestedinahighbayfacility.

• TheprofilerwillbeshippedtoProtoDUNE sitepartiallyassembled(roddisassembledinseveralpieceswithsensorsandcablesinplace,motorandelectronicenclosuredetached)

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InstallationandCommissioning

• WireswillbesolderedtotheD-subconnectorsontheflange.• Cableshieldingwillnotbeconnectedtotheflangeground.• Cableswithtwistedwireswillbesolderedontheuppersideoftheflangeandcableswillbelabeledattatpoint,aftereachsolderingoffourwires.• Sensorreadingwillbecheckedwiththetemp.monitorattherackafterwards,oneatthetime.• Multimeterwillbeusedtocheckthatthecableshieldingisproperlyinsulatedfromtheflangeandtheground.• Motorassemblywillbetested– firstindependentlyofthetemperatureprofiler(motoroperation,encoder,break).Then,itwillbeconnectedtothecarrierrodandtheentireassemblywillbedrivenupanddownthroughallowed1mrange.’• Sensorswillberetestedaftermotorinstallationandconnectiontocarrierrod.

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