Omega LVCN-20 and LVCN-100 Series Owner's manual

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INTRODUCTION/TABLEOFCONTENTS StepOne

The LVCN‐20 and LVCN‐100 Series are general‐purpose level controllers offered in two configurations for

pump and valve control.The LVCN‐100 Series features a single 16A SPDT relay output and can accept one

level sensoras an input.This package has an optional flashing alarm and is ideal for high level or low level

alarm/control.TheLVCN‐20Seriesfeaturesasingle16ASPDTlatchingrelayoutputandcanacceptoneortwo

levelsensor(s)asaninput.Thispackageisidealfortheautomaticfillingoremptyingofatank.Packageeither

controllerserieswithlevelswitch

sensorsandfittings.

Features

 Fail‐Saferelaycontrolofpumps,valvesoralarmswitha0to60seconddelay

 Optionalflashingalarmbringsimmediateattentiontolevelalarmconditions.

 PolypropyleneenclosureratedNEMA4Xwithswivelbaseforconduitalignment.

 EasysetupwithLEDindicatorsfor

sensor(s),powerandrelaystatus.

 InvertswitchchangesrelaystatefromNOtoNCwithoutrewiring.

 ACpowered

TableofContents

Specifications:.........................................................................................................................................................4

Dimensions:.............................................................................................................................................................4

SafetyPrecautions:.................................................................................................................................................5

MakeaFail‐SafeSystem:............................................................................................................................6

Components:...............................................................................................................................................6

GettingStarted:.......................................................................................................................................................7

FeaturesoftheLVCN‐100&LVCN‐110seriesSingleInputController:......................................................7

 FeaturesoftheLVCN‐20seriesDualInputController:..............................................................................7

 GuidetoControls:.......................................................................................................................................8

Electrical..................................................................................................................................................................9

 ConnectingSwitchestoInputTerminals:...................................................................................................9

 VACPowerInputWiring:............................................................................................................................9

 RelayInputWiring:.....................................................................................................................................9

 Changingfrom120to240VAC.................................................................................................................10

Installation............................................................................................................................................................11

ApplicationExmaples............................................................................................................................................12

 LowLevelAlarm:.......................................................................................................................................12

 HighLevelAlarm:......................................................................................................................................12

 LEDIndication:..........................................................................................................................................12

 AutomaticFill:...........................................................................................................................................13

 AutomaticEmpty:.....................................................................................................................................13

Appendix...............................................................................................................................................................14

 ControllerLogic.........................................................................................................................................14

 RelayLatchingLogicTable(LVCN‐20only)...............................................................................................14

 Troubleshooting........................................................................................................................................14

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4

SPECIFICATIONS/DIMENSIONS StepTwo

Controller

Supplyvoltage: 120/240VAC,50‐60Hz.

Consumption: 5Wattsmax.

Sensorinputs: (1)levelswitch

(LVCN‐20seriesonly) (1or2)levelswitches

Sensorsupply: 13.5VDC@27mA

LEDindication: Sensor,relay&powerstatus

Contacttype: (1)SPDTRelay

(LVCN‐20seriesonly) (1)SPDTRelay,Latched

Contactrating: 250VAC,16A

Contactoutput: SelectableNOorNC

Contactdelay: 0to60seconds

Contactlatch: SelectOn/Off‐LVCN‐20only

Electronicstemp.: F:‐40°to158°

 C:‐40°to70°

Enclosurerating: NEMA4X(IP65)

Enclosurematerial: PP(U.L.94VO)

(LVCN‐20seriesonly) PP(U.L.94VO)andPolycarbonate

Enclosuremount.: 3/4”NPT

Enclosurerotation: 300°swivelbase

Conduitentrance: Single,1/2"NPT

Certificatenumber: LR79326‐3

CEcompliance: EN61326EMC

 EN61010‐1Safety

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FlashAlarm(includedwithLVCN‐100only)

Flashtype: Xenontube

Flashfrequency: 1persecond

Strobelife: 10Mcycles

Supplyvoltage: 120VAC,50‐60Hz.

Consumption: 3Wattsmax.

Material: Polycarbonate

Enclosurerating: NEMA4X(IP65)

Color: Amber

SideView

LVCN‐20&LVCN‐110Series

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SideView

LVCN‐100Series

LVCN‐100&LVCN‐110Series LVCN‐20Series FunctionalDiagram

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SAFETYPRECAUTIONS StepThree

AboutThisManual:PLEASEREADTHEENTIREMANUALPRIORTOINSTALLINGORUSINGTHISPRODUCT.

This manual includes information on three different models of Compact Relay Controllers from Omega

Engineering:LVCN‐100, LVCN‐110 and LVCN‐20.The LVCN‐110seriesis a single‐input controllerwith an

optionalFlashAlarmwiththeLVCN‐100series,andtheLVCN‐20isadual‐inputcontroller.Manyaspects

ofinstallationandusearesimilarbetweenthethreemodels.

User’s Responsibility for Safety:OMEGA ENGINEERINGmanufacturesseveralmodelsof controller, with

differentmountingandswitchingconfigurations.Itistheuser’sresponsibilitytoselectacontrollermodel

that is appropriate for the application, install it properly, perform tests of the installed system, and

maintainallcomponents.

Electrical Shock Hazard:It is possible to contact components on the controller that carry high voltage,

causing serious injury or death.All power to the controller and the relay circuit(s) it controls should be 

turned OFF prior to working on the controller.If it is necessary to make adjustments during powered

operation,useextremecautionanduseonlyinsulatedtools.Makingadjustmentstopoweredcontrollers

isnotrecommended.Wiringshouldbeperformedbyqualifiedpersonnelinaccordancewithallapplicable

national,stateandlocalelectricalcodes.

FlammableorExplosiveApplications:Sensormountcontrollersshouldnotbeusedwithexplosiveor

flammableliquids,whichrequireanintrinsicallysafeorexplosionproofrating.Ifyouareunsureofthe

suitabilityofacontrollerforyourinstallation,consultyourOmegaEngineeringrepresentativeforfurther

information.

InstallInaDryLocation:TheLVCN‐100,LVCN‐110&LVCN‐20seriescontrollerhousingisliquid‐resistant

andmadeofPolypropylene(PP).Wheninstalledproperly,thecontrollerisnotdesignedtobeimmersed.

It should be mounted in such a way that it does not normally come into contactwith fluid.Referto an

industryreferencetoensure thatcompoundsthatmay splashontothecontrollerhousingwillnotdamage

it.Suchdamageisnotcoveredbythewarranty.

RelayContactRating:Therelayisratedfora16ampresistiveload.Manyloads(suchasamotorduring

start‐uporincandescentlights)arereactiveandmayhaveaninrushcurrentcharacteristicthatmaybe10

to 20 times their steady‐state load rating.The use of a contact protection circuit may be necessary for

yourinstallationifthe16ampratingdoesnotprovideanamplemarginforsuchinrushcurrents.

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6

SAFETYPRECAUTIONS(cont.) StepThree

Make a Fail‐Safe System:  Design a fail‐safe system that accommodates the possibility of relay or power

failure.If power is cut off to the controller, it will de‐energize the relay.Make sure that the de‐energized

stateoftherelayisthesafestateinyourprocess.Forexample,ifcontrollerpowerislost,apumpfillingatank

willturnoffifitisconnectedtotheNormallyOpensideoftherelay.

While the internal relay is reliable, over the course of time relay failure is possible in two modes: under a

heavyloadthecontactsmaybe“welded”orstuckintotheenergizedposition,orcorrosionmaybuildupona

contact so that it will not complete the circuit when it should.In critical applications, redundant backup

systems and alarms must be used in addition to the primary system.Such backup systems should use

differentsensortechnologieswherepossible.

While this manual offers some examples and suggestions to help explain the operation of OMEGA

ENGINEERINGproducts,suchexamplesareforinformationonlyandarenotintendedasacompleteguideto

installinganyspecificsystem.

Sensor‐mount controllers:The LVCN‐100, LVCN‐110 & LVCN‐20 series are a cost‐effective, modular liquid

level controller whose body incorporates a  female  3/4" NPT (3/4" BSP) fitting, allowing it to be mounted

directly onto any Omega Engineering sensor or any 3/4" connection.Simply provide its required AC power

and a controlled device such as a valve, pump, or alarm that can be switched by the controller’s relay in

responsetothesensorinput.

Sensor‐mountcontrollersareparticularly appropriate for simple processes suchashigh orlowalarms.They

can also be a useful part of more complicated systems, providing a fail‐safe backup in case a centralized

systemfails.

Components:

 LVCN‐110 ‐SingleInputHighorLowRelayController

 LVCN‐110‐CE ‐SingleInputHighorLowRelayControllerwithCEapproval

 LVCN‐100 ‐SingleInputHighorLowRelayControllerwithFlashingAlarm

 LVCN‐100‐CE‐SingleInputHighorLowRelayControllerwithFlashingAlarm&CEapproval

 LVCN‐100‐220VAC ‐SingleInputHighorLowRelayControllerwithFlashingAlarmconfiguredto220VAC

 LVCN‐20‐DualInputAutomaticFillorEmptyRelayController

 LVCN‐20‐CE‐DualInputAutomaticFillorEmptyRelayControllerwithCEapproval

 Owner’sManual

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7

GETTINGSTARTED StepFour

Features ofthe LVCN‐100 &LVCN‐110series Single Input Controller:TheLVCN‐100 & LVCN‐110 series are

designed to receive a signal from a single liquid sensor.It turns its internal relay ON or OFF (as set by the

invertswitch)inresponsetothepresenceofliquid,andchangestherelaystatusbackagainwhenthesensoris

dry.

HighAlarm:

Invert is OFF.Relay will

energize when the switch

becomes Wet and will de‐

energize when the switch

becomesDry(outofliquid).

LowAlarm:

InvertisON.Relaywill energize

when the switch becomes Dry

(out of liquid) and will de‐

energize when the switch

becomesWet.

The LVCN‐100 & LVCN‐110 series may be used with almost any kind of sensor signal: current sensing or

contact closure.The relay is a single pole, double throw type; the controlled device can be connected to

eitherthenormallyopenornormally closed sideoftherelay.Atimedelayfrom0 to60seconds canbeset

before the relay responds to thesensor input.Typicalapplications for theLVCN‐100& LVCN‐110 seriesare

highlevelorlow levelswitch/alarmoperations(openingadrainvalvewheneverliquidlevelrisestoasensor

point)andleakdetection(soundinganalarmwhenaleakisdetected,etc.).

FeaturesoftheLVCN‐20seriesDualInputController:TheLVCN‐20seriesisdesignedtoreceivesignalsfrom

two liquid sensors.It turns its internal relay ON or OFF (as set by the invert switch) in response to the

presenceofliquidonbothsensors,andchangestherelaystatusbackagainwhenbothsensorsaredry.

AutomaticEmpty:

Latch is OFF & Invert is OFF.

Relay will energize when level

reaches high switch (both

switches are wet).Relay

will

de‐energize when level is

belowthebottomswitch(both

switchesaredry).

AutomaticEmpty:

Latch is OFF & Invert is ON.

Relay will energize when level

is below the bottom switch

(both switches are dry).Relay

will de‐energize when level

reaches high switch (both

switchesarewet).

8

GETTINGSTARTED(continued) StepFour

TheLVCN‐20seriesmaybeusedwithalmostanykindofsensorsignal:currentsensingorcontactclosure.The

relayisasinglepole,doublethrowtype;thecontrolleddevicecanbeconnectedtoeitherthenormallyopen

ornormallyclosedsideoftherelay.Atimedelayfrom0to60secondscanbesetbeforetherelayrespondsto

thesensor input.TypicalapplicationsfortheLVCN‐20seriesareautomaticfilling(startingfillpumpatalow

level and stopping pump at a high level) or automatic emptying operations (opening a drain valve at a high

level

andclosingvalveatlowlevel).

GuidetoControls:Belowisalistingandthelocationofthedifferentcomponentsforthecontroller:



1. Powerindicator:ThisgreenLEDlightswhenACpowerisON.

2. Relayindicator:ThisredLEDwilllightwheneverthecontrollerenergizestherelay,in

responsetothe

properconditionatthesensorinput(s)andafterthetimedelay.

3. ACPowerterminals:Connectionof120VACpowertothecontroller.Thesettingmaybechangedto

240VAC ifdesired.Thisrequireschanginginternaljumpers;thisiscoveredintheInstallationsection

ofthemanual.Polarity(neutralandhot)doesnotmatter.

4. Relay terminals (NC, C, NO):Connect the device you wish to control (pump, alarm etc.) to these

terminals: supply to the COM terminal, and the device to the NO or NC terminal as required.The

switched device should be a non inductive load of not more than 16 amps; for reactive loads the

current must be derated orprotection circuits used.When theredLED is ONand the relayisin the

energizedstate,theNOterminalwillbeclosedandtheNCterminalwillbeopen.

5. Invert switch:This DIP switch reverses the logic of the relay control in response to the sensor(s):

conditionsthatusedtoenergizetherelaywillmakeitturnoffandviceversa.

6. Latch switch (LVCN‐20 series only):This DIP switch determines how the relay will be energized in

response to thetwosensor inputs.WhenLATCHis OFF, the relayrespondstosensor Input 1A only;

whenLATCHisON,therelaywillenergizeorde‐energizeonlywhenbothsensors(1Aand1B)areinthe

samecondition(wetordry).Therelaywillremainlatcheduntilbothsensorschangestates.

7. Time

Delay:Aftertheinput(s)change(s)state,thiscontrol setsadelayfrom0.15to60secondsbefore

therelaywillrespond.

8. Input1Aand1Bindicator:TheseamberLEDswilllightimmediatelywhenevertheappropriatesensor

attachedtotheterminalsdetectsliquid,andwillturnoffwhenitisdry.

9. Inputterminals:Connectthewiringfromthesensorstotheseterminals: Atotheupperpair,B(LVCN‐

20 series only) to the lower pair.Note the polarity:(+) is a 13.5 VDC, 27 mA power supply (to be

connectedtotheredwireofanOmegaEngineeringsensor),and(‐)isthereturnpathfromthesensor

(tobeconnectedtotheblackwireofanOmegaEngineeringsensor).Ifpolarityisreversed,thesensors

willnotwork.

9

ELECTRICAL StepFive

Connecting switches to input terminals:Please note a difference between OMEGA ENGINEERING powered

level switches and reed switches.All powered level switches (series LTU‐101, LVU‐150, LVP‐51, LVC‐152 &

LVF‐210) will bewiredwith the Redwireto the (+) terminal and theBlack wire to the (‐) terminal.OMEGA

ENGINEERINGreedswitches(seriesLVV‐110&LVH‐200)willhaveaparticularwiringbaseduponpartnumber.

Seetheillustrationbelowtoindicatewiringforyourswitch.Note:theShieldwirewillbeusedonlyforlong

cablerunsorwhereexcessiveelectricalnoiseis

present.

PoweredLevelSwitches ReedSwitches



SwitchCable:WheninstallinganOmegaEngineering

level switch, adjust the cable away from the printed

circuitboardsin the controller body.Avoid breaking

the seal betweenthe top of thelevel switch and the

plasticcoatedcable.



VAC Power Input Wiring:

Observe the labeling on

the LVCN‐100, LVCN‐110 & LVCN‐20 series.Note:

PolaritydoesnotmatterwiththeACinputterminal.



RelayInputWiring:Therelayisasinglepole,double

throwtyperatedat250VoltsAC,16Amps.Thetwo

terminal NO and NC (normally open

and normally

closed) will be used in different applications.

Rememberthatthe "normal" state is when the relay

coilisde‐energizedandtheRedrelayLEDisOff/de‐

energized.





10

ELECTRICAL(continued) StepFive

Flash Alarm Output (LVCN‐100 series):With the

FlashAlarmwiredNC;itcanbeusedasahighorlow

level alarm, depending on the setting for the invert

switch.TheFlashAlarmcanalsobewiredNO.



Changingfrom120to240VAC:

1. Remove  the two screws from the top of the

printed circuit board (PCB) and gently slide the

PCB from the  housing.Use caution when

removingthePCB.

2. LocatedjumpersJWA,JWBandJWConthePCB.

3. Tochangeto240VAC,removejumpersfromJWB

and JWC and place a single jumper across JWA.

To change to 120 VAC, remove jumper JWA and

placejumpersacrossJWBandJWC.

4. Gently return PCB into housing and replace the

twoscrews.



 120VAC 240VAC

 Configuration Configuration





11

INSTALLATION StepSix

3/4" NPT Mounting Thread:Installation of the compact relay controller takes advantage of the  3/4" NPT

threadlocatedonitsbase.ThismakesthecontrollerfullycompatiblewithanyofOmegaEngineering'slevel

switchesorLVM‐10seriesorLVM‐51Seriesmountingsystems.

Mountingdirectlytoasensor MountingtoLVM‐10Series

LevelTrackMountingSystem

MountingtoLVM‐50Series

SingleSwitchFittingAssembly



Note:Alwaystightenthecontrollerfromthewrenchflatlocatedonthe

swivelbase.Nevertightenfromthebodyofthecontroller.





12

APPLICATIONEXAMPLES StepSeven

LowLevelAlarm:Thegoalistomakesurethattheliquidleveldoesnotfallbelowacertainpoint.Ifitdoes,

analarmissupposedtosound,alertingtheoperatorofalowlevelcondition.

Ifpowerisaccidentallycuttothecontroller,thesensor'sabilitytonotifytheoperatorofalowlevelcondition

couldbelost.Thesystemmustalerttheoperatornotonlytolowliquidlevel,buttocontrollerpowerloss.

To do this, connect the hot lead of the alarm to the NC side of the relay

terminalofthecontroller.Ifpowerislost,therelaywillbede‐energized,and

the alarm will sound (if there is still power to the alarm circuit itself).The

alarm circuit should  have a  non‐interruptible power supply or some other

indicatororbackupalarmtowarnofapowerfailureinthealarmcircuit.

In this application, the normal status if the sensor at the bottom if the tank

will be wet, and the relay will be energized holding the alarm circuit open.

Both the relay LED and the Input LED will be on simultaneously, so for this

application,InvertshouldbesettotheOFFposition.

HighLevelAlarm:Inthesamemanor,thissystemcanbeusedtosoundanalarmwhenfluidreachesahigh

level,withjustachangeinthelocationofthesensorandthesettingoftheInvertswitch.

ThealarmisstillconnectedtotheNCsideoftherelaytoallowforapowerfailurealarm.

Thesensorisnormallydry.Inthiscondition,wewanttherelaytobeenergizedsothealarmdoesnotsound:

i.e.,theRedrelayLEDshouldbeonwhenevertheInputLEDisAmber.SoweturnInvertOn.Ifthefluidlevel

risestothehighsensorpoint,thesensorgoeson,therelayde‐energizes,andthealarmsounds.

LEDIndication:UseLED'slocatedabovetheinputterminalstoindicatewhetherthe

switch is in a wet or dry state.With powered switches, Green indicates dry and

Amberindicateswet.Withreedswitches,AmberindicateswetandnoLEDindicates

dry.Note: reed switches maybe wired in reverse so that wet indicates dry and

Amberindicatesdry.





13

APPLICATIONEXAMPLES(cont.) StepSeven

AutomaticFill:Thissystemconsistsof a tank with a high level sensor, a low

levelsensor,andapumpthatiscontrolledbythecontroller.Partofaproper

fail‐safe design for this particular system is that if power is lost to the

controller for any reason, the pump filling the tank must be turned off.

Therefore,weconnectthepumptotheNOsideoftherelay.Whentherelay

is energized, the pump will turnon andfill the tank.The relayindicator will

corresponddirectlytotheON/OFFstatusofthepump.

NOTE:Ifthepumpmotorloadexceedsthe rating of the  controller’srelay,a

stepperrelayofhighercapacitymustbeusedaspartofthesystemdesign.

DeterminingthesettingsofLATCHandINVERT:Thisisthewaythesystemmustoperate:

 Whenboththehighandlowsensorsaredry,thepumpshouldturnon,startingtofillthetank.

 Whenthelowsensorgetswet,thepumpshouldstayon.

 Whenthehighsensorgetswet,thepumpshouldturnoff.

Latch:Inanytwo‐sensorcontrolsystem,LATCHmustbeON.

Invert:ReferringtothelogicchartinStepNine,welookforthesettingthatwillde‐energizetherelay(start

thepump)whenbothinputsarewet(AmberLEDs).Inthissystem,InvertshouldbeON.

DeterminingAorBinputconnections:WhenLATCHisON,thereisnoeffectivedifferencebetweenInputA

andB,sincebothsensorsmust havethesamesignalinorderforstatustochange.Whenwiringanytwo‐input

relaysection,theonlyconsiderationforhookingaparticularsensortoAorBisifLATCHwillbeOFF.

Automatic Empty:Note that similar system logic can be used for an

automaticemptyoperationsimplybycontrollingapumpthatpumpsfluidout

of the tank instead of into it.However, note the importance of fail‐safe

design.If the tank is being passively filled, and a  pump must be used to

activelyemptyit,apowerfailuretoeitherthecontrollerorthepumpcircuits

willcauseoverflow.

Alternatively,anelectrically‐controlleddrainvalvecouldbeused.Inthiscase,

the valve should be a type that will automatically open if power is lost; in

other words, power must be  used to hold it closed.The valve would be

connectedto

theNOsideoftherelay—ifpowerislosttothecontroller,therelayde‐energizes,thevalveloses

thepowerthatwasholdingitshut,andfluid willdrainfromthetankintosomeothersafecontainmentuntil

power is restored. In this system, whenever the red relay LED of the controller is ON, the drain is closed,

allowingfluidtorise.

Inthiscase,Invertshouldbe ON:whenbothsensorsare wet,therelayde‐energizes,theswitchtothevalve

opens,andthetankwilldrain.





14

APPENDIX StepEight

ControllerLogic:Pleaseusethefollowingguidetounderstandtheoperationofthecontrollers.

1. PowerLED:MakesuretheGreenpowerLEDisONwhenpowerissuppliedtothecontroller.

2. Input LED(s):The input LED(s) on the controller will  be Amber when the switch(es) is/are wet and OFF

whentheswitch(es)is/aredry.IftheLED'sarenotswitchingtheinputLED,testthelevelswitch.

3. LVCN‐100 & LVCN‐110 only:When the input LEDturnOFFandON,therelay LED will alsoswitch.With

invertOFF,therelayLEDwill  beONwhentheinputLEDisONandOFFwhentheinputLEDisOFF.With

invertON,therelayLEDwillbeOFFwhentheinputLEDisONandONwhentheinputLEDisOFF.

4. LVCN‐20 only:When both inputs are wet (Amber LED's ON), the relay will be energized (Red LED ON).

Afterthat,ifone switch becomes dry, the relaywillremainenergized.Onlywhenbothswitchesaredry

(both amber LED's OFF) will the controller de‐energize the relay.The relay will not energize again until

bothswitchesarewet.SeetheRelayLatchLogicChartbelowforfurtherexplanation.

Relay Latch Logic Table (LVCN‐20 only):The relay can either be an independent relay (high or low level

alarm)or can be alatching relay (automatic fillor empty) with latchON.With Latch OFF, the relay willonly

respondtotheINPUT1Asetting.INPUT1Bwillbeignored.

With Latch ON, the relay will

actuatewhenINPUT1AandINPUT

1Bareinthesamecondition.The

relay will not change its condition

until both inputs reverse their

state.

Caution:Some sensors

(particularly buoyancy sensors)

may have their own inverting

capability (wired NO or NC).This

will change the logic of the invert

switch.Checkyoursystemdesign.

Troubleshooting

PROBLEM SOLUTION

Relayswitchesonlyfrom

input1A(ignoresinput1B)

LatchisturnedOFF.FlipthelatchswitchtoturnON.

LevelreachesalarmON,

butrelayisOFF.

First, check to make sure  the input LED is ON.If not,

checkwiringtosensor.

Second, check status of Relay LED.If incorrect, flip the

Invertswitchtochangetherelaystate.

PumporValveissupposed

tostop,butitdoesnot.

First,checktomakesuretheinputLEDsarebothinthe

satestate(bothONorbothOFF).Ifnot,checkwiringto

sensoreachsensor.

Second, check status of Relay LED.If incorrect, flip the

Invertswitchtochangetherelaystate.

Controllerispowered,but

nothinghappens.

First check the Power LED to make sure it is Green.If

not,checkthewiring,powerandmakesuretheterminal

isseatedcorrectlyoverthe6‐pins.

15



16



Omega LVCN-20 and LVCN-100 Series Owner's manual

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