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Instruments & Controls

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FEEDWATER CENTEROverview

Boilerfeedwatercontrolsystemsareoftenthemostarchaiccontrolsinthesteamplant.Poorboilerwatersidecontrolcontributestoscaling,corrosion,andeventuallyhotspotsand tube failures.ThePreferredFeedwater Center can controlthesurgetank,Deaerator(DA)tank,transferpumps,and feedwater pumps (on-off orVSD) to improvewaterqualityandfeedwatersystemreliability.

BetterFeedwaterDeliveryControl• “Smart”PumpSequencing• PumpSpeeddemandbasedStart-Stop• HeaderPressurebasedStart-Stop• Lead-LagSequence• FieldAdjustableParameters

EasytoUse• “Overview”, “Alarm”, “Historical Trend” and “Setup”

displays enable informed initial setup and processassessment.

• In a single NEMA 4 wall-mounted enclosure, theFeedwater Center integrates amodem for off-sitemonitoring,RS485Modbus communications and 24VDCpowersupplies.

• Optional 10”Operator InterfaceTouchscreen (OIT)providesgraphicaloverviewsaswellasEthernetTCP/IPandBacNetIPcommunicationtoBASsystems.

EasytoOrder,StockandFieldUpgrade• Completesystemisorderedusingasinglepartnumber.• “PlugIn”optionboardscanbeusedtoupgradeasystem

inthefield.

Feedwater Center Control System

With the optional 10” color touch screen, trend screens are provided to make it easy to tune level and temperature loops.

Display brings plant overviews, outdoor reset, alarms and event status and setup displays

right to the operator’s touch.Standard Keypad/Display



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Smart Pump SequencingIn“headeredmode,”pumpsareautomaticallysequencedon/off to ensure that the number of pumps in servicemeetsthedemand.Ifanypumpfailstostartwhencalled,the Feedwater Center immediately starts another pumptoreplacethefaultedpump.Theoperatormaymanuallyselect the lead pump or allow the lead pump to rotateautomatically. Additionally, the total number of pumpsin servicemay be set automatically ormanually by theoperator or all pumps may be shutdown by a buildingautomationsystem(BAS)‘enable/disable’contactinput.

Easy Installation & SetupTheFeedwaterCenterintegratesModbuscommunications,relays,24VDCpowersupplies,andoutdoorresetfunctionsintoasinglewallmountablecontroller.Simplemenu-stylefill-in-the-blanks setup displays minimize commissioningandtrainingtime.

LCD Graphic DisplayLCDgraphicdisplaybringsplantoverviews,outdoorreset,alarms and event status and setup displays right to theoperator’stouch.

Alarms & Event SummaryUp to 200 alarms, system events and operator actionsarelistedin“firstinfirstout”orderwithatime/datestamp.Alarms includesystemfault,pump failureandbothoverandundertemperatureconditions.

Hard Manual BackupHardwired control switches and dials provide simplemanual control for easy troubleshooting and service.Eachpumphasanindividualspeeddemandbargraph,amanualspeeddemandoutputknob,andanauto/manualswitch.

Modbus Communication InterfaceAfactoryconfiguredRS485MODBUSinterfaceisavailableforbuildingautomationorSCADAsystemmonitoringandcontrol.

Optional FeaturesThe Feedwater Center has many features that can beaddedorremovedaccordingtoyourneeds.Thiscontrollerwasdesignedtoaccommodatetheneedsofany1-4pumpsystem.Itisabletorunwithasurgeandadeaeratortank(oroneofeach,ornone).Itaccommodates0-3transferpumpsand0-4feedwaterpumps.TheJC-FWC-FCcanbeusedinheaderedpumpapplicationsaswellasindividualfeedwaterpumps toeachboiler. TheJC-FWC-FCcanhaveallofthesefollowingsensors;

Temperature:CondensateReturnLineDATank

Pressure:DATankFeedwaterHeaderSteamHeaderMakeUpWater

Level:1DATank1SurgeTank

Flow:MakeUpWaterFlowCondensateReturnFlow

Aswellascontrolling thespeedsofup to three transferpumpsandfourboilerfeedpumps.TheFeedwaterCentercontrols a number of valves in order tomaintain levels/pressures/flowrateswithinthesystem.

Thefollowingvalvescanbemaintained:

DALevelValveDAPSIControlValveSurgeTankMakeUpWaterValveChemicalFeedPumpValve

Thissystemiseasilyconfiguredbyusingthemenudriveninitial set-up screens. No programming knowledge isrequired.


Feedwater Center Control System shown with optional 10” color touch screen OIT



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FEEDWATER CENTERTouchScreenOverview

Tuning PageTuningpagesallowtheusertoviewcontrolloopsfortuningpurposes.HistoricaldataissavedtoacompactflashcardandcanbeviewedthroughaPC.

Touch Screen OverviewTheoptional10”OperatorInterfaceTerminal(OIT)touchscreenprovidesgraphicalrepresentationofcurrentsystemstatus.Pump status, level indication, and valve positionareallreadilyavailableonthesystemoverviewpage.

Setup ParametersAllparametersareavailablethroughthesetuppagesonthe touchscreen.System featuresandcontrol logicareadjusteddependingontheinitialsetupparameters.

Alarm PageThealarmandeventsscreenlistsallcurrentalarmsandallrecentcontrolevents.Thisscreenhelpsdiagnoseboilerbeforetheyimpactboileroperation.



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JC-FWC-xxx -FC -NV -NS -NVS FieldDevice

Digital InputsFWPumpRunning 4 4 4 4 120VAC-(e.g.currentsensingrelay)BoilerRunning/CallForWater 4 4 4 4 120VAC-BLRRun/DrumLevelSwitchTPPumpRunning 3 3 120VAC-CSR/AuxContactMotorstarterDALowLevelCutoffSwitch 1 1 1 1 120VAC-LevelSwitchSTLowLevelCutoffSwitch 1 1 1 120VAC-LevelSwitchWaterSoftenerAlarm 1 1 1 1 120VAC-ContactFromSoftenerDisable 1 1 1 1 120VAC-ContactFromBAS

Analog InputsDALevel 1 1 1 1 4-20mALevelTransmitterDATemperature 1 1 1 Thermowell(partnumbers70610,70611)DAPSI 1 1 1 4-20mAPSITransmitter(partnumber7060X)FWHeaderPSI 1 1 1 1 4-20mAPSITransmitter(partnumber7060X)SteamPSI 1 1 1 4-20mAPSITransmitter(partnumber7060X)*MakeupFlow 1 1 1 4-20mAFlowMeterMakeupPressure 1 1 1 4-20mAPSITransmitter(partnumber7060X)Condensate Return Temperature 1 1 1 Thermowell(partnumbers70610,70611)CondensateReturnFlow 1 1 1 4-20mAFlowMeterSurgeTankLevel 1 1 4-20mALevelTransmitter

Digital OutputsFWPumpStart 4 4 4** 4** DryContact(closetostart)TPPumpStart 3 3 DryContact(closetostart)WaterSoftenerRegenCycle 1 1 1** DryContact(closetostart)

Analog OutputsFWPumpSpeed 4 4 4-20mAOutputTPPumpSpeed 3 4-20mAOutputSTMUWaterValve 1 1 4-20mAOutputChemFeedPump 1 1 1 4-20mAOutputDAPSIControlValve 1 1 1 4-20mAOutputDALevelControlValve 1 1 1 4-20mAOutput

ThePreferredFeedwaterCenterisavailableinfourmodels,eachwithdifferentcapabilities.Toselectthecorrectmodelforeachapplication, consult thehardwareconfigurations, input/outputsprovided,andsample specificationson thefollowingpages.

Catalog Number Description PWC Hardware

Configuration

JC-FWC-FC Full Control PWCN4-CDROOOA

JC-FWC-NV NoVSDs PWCN4-CDROxxA

JC-FWC-NS NoSurgeTank/TransferPumps PWCN4-CDHOOxA

JC-FWC-NVS NoVSDsandnoSurgeTank/TransferPump PWCN4-CDHxxxx

BelowisacompletelistoftheinputsandoutputsforeachofthefourFeedwaterCentermodels.

*Steam PSI transmitter must be scaled similar to the Feedwater PSI transmitter**HOA switches provided on -NS and -NVS models



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FEEDWATER CENTERSpecifications

Mechanical:EnclosureSize: 35”Hx20”Wx10”DEnclosureType: Wallmount,NEMA4MountingHolePattern: (4)5/16”dia.Weight: 70lbs.

EnvironmentalOperatingTemp: 32°to122°F(0°to50°C)StorageTemp: -20°to150°F(-28°to65°C)HumidityLimits: 15%to95%(noncondensing)Enclosure: NEMA4

PerformanceAccuracy: 0.025%analogI/OResolution: 16bitinput/12bitoutputMicroprocessor: 32bit,128kEEPROMExecutionCycle: FivepersecondTime/DateClock: (batterybacked)

Operator Control PanelLCDDisplay: 2.9"Hx5.1"WKeyboard: Membrane,tactilefeedback

ConfigurationStandardLead/Lag: Menustyle

“Fill-In-The-Blanks”setup.ControlLanguage: Functionblockstyle,

60functions,600BlocksCustomBlockwareConfigurationSoftware: PWC_Edit™ spreadsheetbased

or PWC_Draw™ graphical,editor.(WindowsPCRequired)

CommunicationControlNetwork:Protocol: Modbus(ASCIIorRTUmode)Speed: 1200to38,400baudType: RS485,opticallyisolated

ProgrammingPort:Speed: 38,400baudType: RS232,DB9Fconnector

ElectricalInputPower: 120VAC(+/-15%),12Atotal,

0.7AinternalBuilt-insurgesuppressors

InternalPowerSupply: 24VDC@300mADCfor

external use



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FEEDWATER CENTER MODEL JC-FWC-FCFeedwaterDeliveryController

ApplicationTheFeedwaterCenterModel JC-FWC-FC includesallavailablefeatures and capabilities required to control feedwaterdeliverysystemsincludingDAlevelandpressurecontrol,surgetanklevelcontrol,transferpumpcontrol,feedwaterpump control, chemical feed pump control andwatersoftenerregeneration.

JC-FWC-FC, Full Control

Up to 4 Feedwater PumpsPumpsuse“smart”sequencingtoensurethepropernumberofpumpsarerunningtosatisfythefeedwaterdemand.

deaerator tank

surge tank

Boiler 1 Run (Boiler Limits, One per Boiler)

Surge Tank Make Up Water Valve

Surge Tank Low Level Sensor

DA Tank Level Control Valve

DA Tank Level

To Boilers (Header Piped or Optional Per Boiler Set Up)

DA Tank PSI

Chemical Feed Valve

Feedwater Pumps

Transfer Pumps

Condensate Return Line Temperature

DA Tank Temperature

FW H

eade

r PSI

Proof of FlowBoiler Feedwater Pump ONBoiler Feedwater Pump Speed Control

Proof of FlowTransfer Pump ONTransfer Pump Speed Control

DA Tank PSI Control Valve

DA Tank Low Level Sensor

PT LT TELS

PS

Chem

ical F

eed

Make Up Water Line

Water Softener

Typical Per Pump

Typical Per Pump

Condensate Return Line Flow

Steam Header Pressure

LS

Surge Tank Level

LTPT FT

Make Up Water PSIMake Up Water Flow

Soft Water Regen



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FEEDWATER CENTER MODEL JC-FWC-FCFeedwaterDeliveryController-Specification

1. ApplicationSupplyafullyintegratedFeedwaterControlsystemtocoordinatetheoperationof(upto)fourVSDcontrolledFeedwaterpumps,Daearatorlevelandpressurecontrol,(upto)threetransferpumps,watersoftenerregenerationandchemicalfeed.Thecontrolsystemshallbemicroprocessor-basedandsuitableforwallmounting.2. Pump VSD ModulationThecontrol systemshallprovideaPIDbasedcontrol scheme.Asdemandincreases,thespeedofthepumpwillincrease.Eachrunningpumpwillmodulateinunison.Modulationsignalsshallbe4-20mADCandshallbeelectricallyisolatedchannel-channelandchannel-ground.3. Headered Feedwater Pressure SetpointTheFeedwaterpressuresetpointmustbefieldselectablebetweensteamheaderbasedormanual.Insteamheaderbasedmode,theFeedwaterpressuresetpointmustbecalculatedbasedonanadjustabledeviationfromtheactualsteamheaderpressure.Inmanual, theoperatormaysettheFeedwaterHeaderPressureSetpointviaafrontpaneldisplay.4. Pump SequenceThecontrolsystemshallusebothFeedwaterheaderpressure(Deaerator level for transfer pumps) andpumpspeed to startandstopthepumpsandminimizethetotalnumberofpumpsinoperation.Thecontroller shall startandstoppumpswhen theFeedwaterheaderpressureisoutsideanadjustablepressurelimitbandforlongerthananadjustableshorttimedelay.Toanticipateandminimize header pressure deviations, the control systemshallstartorstopthenextpumpifthe“lead”pumphasbeennearmaximumorminimumspeedforlongerthantheadjustabletimedelay.Thecontrolsystemshallmonitoreachpump’sflowswitchandshallrapidlyandautomaticallyreplaceanypumpthatfailsto prove flow.The leadpumpshall either automatically rotateonatimeofday/dayofweek(ormonth)schedule,orshallbemanuallyselectedbytheoperator.Thecontrolsystemshallbefieldadjustableto“perboiler”modewhichwouldrunonefeedwaterpumpper boiler.Additionally, the control systemshall be fieldadjustabletochoosebetweenheaderedorboilerspecificpipingtodeterminewhichpumpsshouldbestarted.A120VACDiscreteinputistobeprovidedasaDeaeratorlowlevelsignalthatdisablesallFeedwaterPumps.A120VACDiscreteinputistobeprovidedasasurgetanklowlevelsignalthatdisablesalltransferpumps.5. Deaerator ControlThecontrolsystemshalloutputademandsignalbasedonDALevel. When usedwith transfer pumps, this is the speed atwhichthetransferpumpsmustrun.Withouttransferpumps,thiswoulddrivealevelcontrolvalve.ThecontrolsystemshalldriveaDeaeratorpressurecontrolvalvebasedonDeaeratorpressure.6. Surge Tank ControlThe control system shall output a command to a freshwatermakeupvalvebasedonsurgetanklevel.Fieldadjustablelevelforvalveat0%openandvalveat100%openshallbeprovided.

7. Chemical Feed ControlThecontrolsystemshallmonitormakeupwaterflowandsendthatflowsignaltoachemicalfeedpump.8. Soft Water Regeneration ControlThecontrolsystemshallinitiateasoftwaterregenerationcyclebasedontime,oruponreceivingasoftwateralarm.Theoperatorshall alsobeable to initiate the softwater regeneration cyclemanually.9. Monitor PointsThecontrolsystemshallmonitorDeaerator temperature, freshwatermakeuppressure,condensatereturnflowandcondensatereturntemperaturefordisplaypurposes.10. Operator Controls, Trends, Indications and AlarmsThe control system shall include a 16 line x 40 character (orgreater)LCDdisplayforboilersequencecontrolandstatus,alarmandeventsummaries,andsetupmenusforeasyoperation,tuningandtroubleshooting.Alarms,eventsandoperatoractionsshallbeloggedwithtime/datestampandEnglishlanguagedescription.11. CommunicationTheControl System shall have the ability of simultaneouslycommunicating to aDataAcquisitionSystem (DAS),BuildingAutomation System (BAS) or BuildingManagement System(BMS)viaRS485Modbusprotocolandtoapersonalcomputer.Theindividualboilerlimits,lockout,start/stop,warmstandby,andfiringratestatusshallbeeasilyread.Headersetpoint,plantfiringrate,boilerquantitycalledtostart,boilerselectedasleadandallsetupparametersshallbereadableandwritable.12. Quality AssuranceThe control system shall bemanufactured and labeled inaccordancewithUL508requirements(CSAC22.2#14foruseinCanada).InspectionandlabelingshallbesupervisedbyULorotherOSHAapprovedNationallyRecognizedTestLab(NRTL).Thecontrol systemshall beaPreferred Instruments,Danbury,CT,Model JC-FWC-FC.



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FEEDWATER CENTER MODEL JC-FWC-NVFeedwaterDeliveryController

ApplicationTheFeedwaterCenterModel JC-FWC-NV includesallavailablefeatures and capabilities required to control feedwaterdeliverysystemsincludingDAlevelandpressurecontrol,surgetanklevelcontrol,transferpumpcontrol,feedwaterpump control, chemical feed pump control andwatersoftenerregeneration.

JC-FWC-NV, Full Control for pumps without VSDs

Up to Four Feedwater PumpsPumpsuse“smart”sequencingtoensurethepropernumberofpumpsarerunningtosatisfythefeedwaterdemand.

deaerator tank

surge tank


Surge Tank Make Up Water Valve

Surge Tank Low Level Sensor


DA Tank Level


DA Tank PSI

Chemical Feed Valve

Feedwater Pumps

Transfer Pumps

Condensate Return line Temperature

DA Tank Temperature

FW H

eade

r PSI

Proof of FlowBoiler Feedwater Pump ON

Proof of flowTransfer Pump ON



PT LT TE

LS

PS

Chem

ical F

eed

Make Up Water Line

Water Softener

Typical Per Pump

Typical Per Pump

Condensate Return line Flow


LS

Surge Tank Level

LTPT FT


Soft Water Regen



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FEEDWATER CENTER MODEL JC-FWC-NVFeedwaterDeliveryController-Specification

1. ApplicationSupplyafullyintegratedFeedwatercontrolsystemtocoordinatetheoperationof(upto)fourFeedwaterpumps,Daearatorlevelandpressurecontrol,(upto)threetransferpumps,watersoftenerregeneration and chemical feed.The control system shall bemicroprocessor-basedandsuitableforwallmounting.2. Headered Feedwater Pressure SetpointTheFeedwaterpressuresetpointmustbefieldselectablebetweensteamheaderbasedormanual.Insteamheaderbasedmode,theFeedwaterpressuresetpointmustbecalculatedbasedonanadjustabledeviationfromtheactualsteamheaderpressure.Inmanual,theoperatormaysettheFeedwaterheaderpressuresetpointviaafrontpaneldisplay.3. Pump SequenceThe control system shall use Feedwater Header Pressure(Deaerator Level for Transfer Pumps) to start and stop thepumpsandminimize the total number of pumps in operation.Thecontrollershallstartandstoppumpswhen theFeedwaterheaderpressureisoutsideanadjustablepressurelimitbandforlongerthananadjustableshorttimedelay.Thecontrolsystemshallmonitor each pump’s flow switch and shall rapidly andautomaticallyreplaceanypumpthatfailstoproveflow.Theleadpumpshalleitherautomaticallyrotateonatimeofday/dayofweek(ormonth)schedule,orshallbemanuallyselectedbytheoperator.Thecontrolsystemshallbefieldadjustableto“perboiler”modewhichwouldrunonefeedwaterpumpperboiler.Additionally,thecontrolsystemshallbefieldadjustabletochoosebetweenheadered or boiler specific piping to determinewhich pumpsshouldbestarted.A120VACDiscreteinputistobeprovidedasaDeaeratorlowlevelsignalthatdisablesallFeedwaterpumps.A120VACDiscreteinputistobeprovidedasasurgetanklowlevelsignalthatdisablesalltransferpumps.4. Deaerator ControlThecontrolsystemshalloutputademandsignalbasedonDAlevel.Whenusedwithtransferpumps,thisisthespeedatwhichthetransferpumpsmustrun.Withouttransferpumps,thiswoulddrivealevelcontrolvalve.ThecontrolsystemshalldriveaDeaeratorpressurecontrolvalvebasedonDeaeratorpressure.5. Surge Tank ControlThe control system shall output a command to a freshwatermakeupvalvebasedonsurgetanklevel.Fieldadjustablelevelforvalveat0%openandvalveat100%openshallbeprovided.6. Chemical Feed ControlThecontrolsystemshallmonitormakeupwaterflowandsendthatflowsignaltoachemicalfeedpump.7. Soft Water Regeneration ControlThecontrolsystemshallinitiateasoftwaterregenerationcyclebasedontime,oruponreceivingasoftwateralarm.Theoperatorshall alsobeable to initiate the softwater regeneration cyclemanually.

8. Monitor PointsThecontrolsystemshallmonitorDeaerator temperature, freshwatermakeuppressure,condensatereturnflowandcondensatereturntemperaturefordisplaypurposes.9. Operator Controls, Trends, Indications and AlarmsThe control system shall include a 16 line x 40 character (orgreater)LCDdisplayforboilersequencecontrolandstatus,alarmandeventsummaries,andsetupmenusforeasyoperation,tuningandtroubleshooting.Alarms,eventsandoperatoractionsshallbeloggedwithtime/datestampandEnglishlanguagedescription.10. CommunicationThe control system shall have the ability of simultaneouslycommunicating to aDataAcquisitionSystem (DAS),BuildingAutomation System (BAS) or BuildingManagement System(BMS)viaRS485Modbusprotocolandtoapersonalcomputer.Theindividualboilerlimits,lockout,start/stop,warmstandby,andfiringratestatusshallbeeasilyread.Headersetpoint,plantfiringrate,boilerquantitycalledtostart,boilerselectedasleadandallsetupparametersshallbeeasilyreadandwritten.11. Quality AssuranceThe control system shall bemanufactured and labeled inaccordancewithUL508requirements(CSAC22.2#14foruseinCanada).InspectionandlabelingshallbesupervisedbyULorotherOSHAapprovedNationallyRecognizedTestLab(NRTL).Thecontrol systemshall beaPreferred Instruments,Danbury,CT,Model JC-FWC-NV.



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FEEDWATER CENTER MODEL JC-FWC-NSFeedwaterDeliveryController

ApplicationTheFeedwaterCenterModel JC-FWC-NS includesallavailablefeatures and capabilities required to control feedwaterdeliverysystemsincludingDAlevelandpressurecontrol,feedwaterpumpcontrol,chemicalfeedpumpcontrolandwatersoftenerregeneration.

JC-FWC-NS, Full Control for systems without surge tanks


deaerator tank



DA Tank Level


DA Tank PSI

Chemical Feed Valve

Feedwater Pumps

Condensate Return Line Temperature

DA Tank Temperature

FW H

eade

r PSI

Proof of FlowBoiler Feedwater Pump ONBoiler Feedwater Pump Speed Control



PT LT TE

LS

PS

Chem

ical F

eed

Make Up Water Line

Water Softener

Typical Per Pump

Condensate Return Line Flow


PT FT


Soft Water Regen



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FEEDWATER CENTER MODEL JC-FWC-NSFeedwaterDeliveryController-Specification

1. ApplicationSupplyafullyintegratedFeedwatercontrolsystemtocoordinatetheoperationof(upto)fourVSDcontrolledFeedwaterpumps,Daearatorlevelandpressurecontrol,watersoftenerregenerationandchemicalfeed.Thecontrolsystemshallbemicroprocessor-basedandsuitableforwallmounting.2. Pump VSD ModulationThecontrol systemshallprovideaPIDbasedcontrol scheme.Asdemandincreases,thespeedofthepumpwillincrease.Eachrunningpumpwillmodulateinunison.Modulationsignalsshallbe4-20mADCandshallbeelectricallyisolatedchannel-channelandchannel-ground.3. Headered Feedwater Pressure SetpointTheFeedwaterpressuresetpointmustbefieldselectablebetweensteamheaderbasedormanual.Insteamheaderbasedmode,thefeedwaterpressuresetpointmustbecalculatedbasedonanadjustabledeviationfromtheactualsteamheaderpressure.Inmanual, theoperatormayset theFeedwaterheaderpressuresetpointviaafrontpaneldisplay.4. Pump SequenceThecontrolsystemshallusebothFeedwaterheaderpressureandpumpspeedtostartandstopthepumpsandminimizethetotal number of pumps in operation.The controller shall startandstoppumpswhentheFeedwaterheaderpressureisoutsideanadjustablepressurelimitbandforlongerthananadjustableshort timedelay.Toanticipate andminimizeheader pressuredeviations,thecontrolsystemshallstartorstopthenextpumpifthe“lead”pumphasbeennearmaxorminspeedforlongerthantheadjustabletimedelay.Thecontrolsystemshallmonitoreachpump’sflowswitchandshall rapidlyandautomaticallyreplaceanypump that fails to prove flow.The leadpumpshall eitherautomatically rotateona timeofday/dayofweek (ormonth)schedule,or shall bemanually selectedby theoperator. Thecontrolsystemshallbefieldadjustableto“perboiler”modewhichwouldrunonefeedwaterpumpperboiler.Additionally,thecontrolsystemshallbefieldadjustabletochoosebetweenheaderedorboilerspecificpipingtodeterminewhichpumpsshouldbestarted.A120VACDiscreteinputistobeprovidedasaDeaeratorlowlevelsignalthatdisablesallFeedwaterpumps.5. Deaerator ControlThecontrolsystemshall triggerademandsignalbasedonDALevel.When usedwith transfer pumps, this is the speed atwhichthetransferpumpsmustrun.Withouttransferpumps,thiswoulddrivealevelcontrolvalve.ThecontrolsystemshalldriveaDeaeratorpressurecontrolvalvebasedonDeaeratorpressure.6. Chemical Feed ControlThecontrolsystemshallmonitormakeupwaterflowandsendthatflowsignaltoaChemicalfeedpump.7. Soft Water Regeneration ControlThecontrolsystemshallinitiateasoftwaterregenerationcyclebasedontime,oruponreceivingasoftwateralarm.Theoperatorshallalsobeabletomanuallystartthesoftwaterregenerationcycle.

9. Monitor PointsThecontrolsystemshallmonitorDeaerator temperature, freshwatermakeuppressure freshwatermakeup flow, condensatereturn flow and condensate return temperature for displaypurposes.10. Operator Controls, Trends, Indications and AlarmsThe control system shall include a 16 line x 40 character (orgreater)LCDdisplayforboilersequencecontrolandstatus,alarmandeventsummaries,andsetupmenusforeasyoperation,tuningandtroubleshooting.Alarms,eventsandoperatoractionsshallbeloggedwithtime/datestampandEnglishlanguagedescription.11. ReliabilityIncludehardwiredbackupstations topermitmanual operationoftheplantshouldthecontrolsystemrequireservice.Manualoperationmust be possiblewhen themicroprocessor is notfunctioning.Hardwired “hand-off-auto” control switchesmustbewireddirectlyintoeveryboilerstart/stopcircuit.Each4-20mADCor0-135ohmmodulatingcontroloutputmust includeahardwiredmanualbackupstationwithauto/manualswitch,outputcontrolknobandoutputlevelindicator(bargraph,analogmeterordigitaldisplay).12. CommunicationThe control system shall be capable of simultaneouslycommunicating to aDataAcquisitionSystem (DAS),BuildingAutomation System (BAS) or BuildingManagement System(BMS)viaRS485Modbusprotocolandtoapersonalcomputer.Theindividualboilerlimits,lockout,start/stop,warmstandby,andfiringratestatusshallbeeasilyread.Headersetpoint,plantfiringrate,boilerquantitycalledtostart,boilerselectedasleadandallsetupparametersshallbeeasilyreadandwritten.13. Quality AssuranceThe control system shall bemanufactured and labeled inaccordancewithUL508requirements(CSAC22.2#14foruseinCanada).InspectionandlabelingshallbesupervisedbyULorotherOSHAapprovedNationallyRecognizedTestLab(NRTL).Thecontrol systemshall beaPreferred Instruments,Danbury,CT,Model JC-FWC-NS.



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FEEDWATER CENTER MODEL JC-FWC-NVSFeedwaterDeliveryController

ApplicationThe Feedwater CenterModel JC-FWC-NVS includes allavailable features and capabilities required to controlfeedwaterpumps.

JC-FWC-NVS, Full Control for systems without surge tank or VSD controlled pumps


deaerator tank


DA Tank Level


Feedwater Pumps

FW H

eade

r PSI

Proof of FlowBoiler Feedwater Pump ON


LT

LSPS

Typical Per Pump



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FEEDWATER CENTER MODEL JC-FWC-NVSFeedwaterDeliveryController-Specification

1. ApplicationSupplyafullyintegratedFeedwatercontrolsystemtocoordinatetheoperationof(upto)fourFeedwaterpumps.Thecontrolsystemshallbemicroprocessor-basedandsuitableforwallmounting.2. Headered Feedwater Pressure SetpointTheFeedwaterpressuresetpointmustbefieldselectablebetweenSteamheaderbasedormanual.Insteamheaderbasedmode,theFeedwaterpressuresetpointmustbecalculatedbasedonanadjustabledeviationfromtheactualSteamheaderpressure.Inmanual,theoperatormaysettheFeedwaterheaderpressuresetpointviaafrontpaneldisplay.3. Pump SequenceThecontrolsystemshalluseFeedwaterheaderpressuretostartandstopthepumpsandminimizethetotalnumberofpumpsinoperation.Thecontroller shall startandstoppumpswhen theFeedwaterheaderpressureisoutsideanadjustablepressurelimitbandforlongerthananadjustableshorttimedelay.Thecontrolsystemshallmonitoreachpump’sflowswitchandshallrapidlyandautomaticallyreplaceanypumpthatfailstoproveflow.Theleadpumpshalleitherautomaticallyrotateonatimeofday/dayofweek(ormonth)schedule,orshallbemanuallyselectedbytheoperator.Thecontrolsystemshallbefieldadjustableto“perboiler”modewhichwouldrunonefeedwaterpumpperboiler.Additionally,thecontrolsystemshallbefieldadjustabletochoosebetweenheadered or boiler specific piping to determinewhich pumpsshouldbestarted.A120VACDiscreteinputistobeprovidedasaDeaeratorlowlevelsignalthatdisablesallFeedwaterpumps.4. Operator Controls, Trends, Indications and AlarmsThe control system shall include a 16 line x 40 character (orgreater)LCDdisplayforboilersequencecontrolandstatus,alarmandeventsummaries,andsetupmenusforeasyoperation,tuningandtroubleshooting.Alarms,eventsandoperatoractionsshallbeloggedwithtime/datestampandEnglishlanguagedescription.Thecontrolsystemshallincludeaminimumof200pointmemory.5. ReliabilityIncludehardwiredbackupstations topermitmanual operationof theplantshould thecontrolsystemrequireservice.Manualoperationmust be possiblewhen themicroprocessor is notfunctioning.Hardwired “hand-off-auto” control switchesmustbewireddirectlyintoeveryboilerstart/stopcircuit.Each4-20mADCor0-135ohmmodulatingcontroloutputmust includeahardwiredmanualbackupstationwithauto/manualswitch,outputcontrolknobandoutputlevelindicator(bargraph,analogmeterordigitaldisplay).

6. CommunicationThe control system shall have the ability of simultaneouslycommunicating to aDataAcquisitionSystem (DAS),BuildingAutomation System (BAS) or BuildingManagement System(BMS)viaRS485Modbusprotocolandtoapersonalcomputer.Theindividualboilerlimits,lockout,start/stop,warmstandby,andfiringratestatusshallbereadable.Headersetpoint,plantfiringrate,boilerquantitycalledtostart,boilerselectedasleadandallsetupparametersshallbeeasilyreadandwritten.7. Quality AssuranceThe control system shall bemanufactured and labeled inaccordancewithUL508requirements(CSAC22.2#14foruseinCanada).InspectionandlabelingshallbesupervisedbyULorotherOSHAapprovedNationallyRecognizedTestLab(NRTL).Thecontrol systemshall beaPreferred Instruments,Danbury,CT,Model JC-FWC-NS.

Feedwater Center Cutsheet - Home | Preferred Utilities Mfg...Boiler feedwater control systems are...

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