Copyright HK Instruments 2022 www.hkinstruments. Installaon version 8.0 2022
INSTALLATION
INSTRUCTIONS
HUMIDITY TRANSMITTERS
RHT Series
• READ THESE INSTRUCTIONS CAREFULLY BEFORE ATTEMPTING
TO INSTALL, OPERATE OR SERVICE THIS DEVICE.
• Failuretoobservesafetyinformaonandcomplywithinstrucons
canresultinPERSONALINJURY,DEATHAND/ORPROPERTY
DAMAGE.
• Toavoidelectricalshockordamagetoequipment,disconnect
powerbeforeinstallingorservicinganduseonlywiringwith
insulaonratedforfulldeviceoperangvoltage.
• Toavoidpotenalreand/orexplosiondonotuseinpotenally
ammableorexplosiveatmospheres.
• Retaintheseinstruconsforfuturereference.
• Thisproduct,wheninstalled,willbepartofanengineeredsystem
whosespecicaonsandperformancecharacteriscsarenot
designedorcontrolledbyHKInstruments.Reviewapplicaons
andnaonalandlocalcodestoassurethattheinstallaonwill
befunconalandsafe.Useonlyexperiencedandknowledgeable
technicianstoinstallthisdevice.
•Fuseatloadsupply(normally6A,10A,16A)doesnotalwayslimit
therelayoutputloadcurrentto6A.RelayMaximumLoad(250Vx
6Ares.)
•Addanexternalfusetorelaycommonconnector.Useame-lag
fuse(max6A)thatisinaccordancewiththestandardIEC60127-2.
Theproductdoesn’thaveaninternalfusefortherelay.
CAUTION:Theproductmayonlybeconnectedtoovervoltage
categoryIIelectricitynetworkaccordingtoIEC60664-1
SPECIFICATIONS
ThankyouforchoosinganHKInstrumentsRHTseriesrelavehu-
miditytransmier.TheRHTseriesisintendedforuseincommercial
environmentsinHVAC/Rapplicaons.
TheRHTseriesmeasuresrelavehumidity(rH)andtemperature(T).
Eachmeasurementparameter(rH,T)hasaseparateeldcongur-
ableoutput.
The RHT series relave humidity transmiers are available with
Modbusconguraon,relayandtouchscreendisplay.
RHTseriesdevicesarecommonlyusedtomonitor:
•humidityandtemperaturelevelsinoces,publicspaces,hospitals,
meengroomsandclassrooms
•humidityandtemperatureinvariouscommercialapplicaons
•humidityandtemperatureinHVAC/Renvironment
SPECIFICATIONS
Performance
Measurement ranges:
Temperature:0...50°C
Relavehumidity:0–100%
Accuracy:
Temperature:<0.5ºC
Relavehumidity:±2...3%at0...50°Cand10–90%rH
Totalerrorbandincludesaccuracy,hysteresisand
temperatureeectover5...50°Cand10–90%rH.
Technical Specicaons
Media compability:
Dryairornon-aggressivegases
Measuring units:
°Cand%rH
Measuring element:
Temperature:Integrated
Relavehumidity: Thermosetpolymercapacive
sensingelement
Environment:
Operangtemperature:0...50°C
Storagetemperature:-20...70°C
Humidity:0to95%rH,noncondensing
Physical
Dimensions:
Case:99x90x32mm
Weight:
150g
Mounng:
3screwholessloed,3.8mm
Materials:
Case: ABS
Protecon standard:
IP20
Display (Oponal)
Touchscreen
Size:77.4x52.4mm
Electrical connecons:
Powersupply:
5-screwterminalblock
(24V,GND,rH,T,Maxvalue)
0.2–1.5mm2(16–24AWG)
Relay out:
3-screwterminalblock
(NC,COM,NO)
0.2–1.5mm2(16–24AWG)
Electrical
Input: 24VACorVDC,±10%
Currentconsumpon:max90mA(at24V)+
10mAforeachvoltageoutputor20mAforeach
currentoutput
Outputsignal(rH,temperature):
0–10V,R>1kΩ
2–10V,R>1kΩ(oponalvoltageoutput,displayrequired)
4–20mA,R<500Ω
Relay out:
SPDTRelay,250VAC/30VDC/6A
Adjustableswitchingpointandhysteresis
Conformance
Meetsrequirementsfor:
CE: UKCA:
EMC: 2014/30/EU S.I.2016/1091
RoHS: 2011/65/EU S.I.2012/3032
LVD/EESR: 2014/35/EU S.I.2016/1101
WEEE: 2012/19/EU S.I.2013/3113
INTRODUCTION WARNING
APPLICATIONS
RoHS
COMPLIANT
Copyright HK Instruments 2022 www.hkinstruments. Installaon version 8.0 2022
SCHEMATICS
DIMENSIONAL DRAWINGS
INSTALLATION
STEP 1: MOUNTING THE DEVICE
1)Mountthedeviceinthedesiredlocaon(seestep1).
2)Routethecablesandconnectthewires(seestep2).
3)Thedeviceisnowreadyforconguraon.
WARNING!Applypoweronlyaerthedeviceisproperlywired.
Figure 1a - Surface mounng
Display locking
jumper
Jumpers
Contact pins for
relay terminal
Contact pins for
terminal block
Terminal block
Terminal block for relay
99.0
90.0
83.0
49.5
14.0
45.0
18.0
Ø 4.0
32.0
YES NO NO
Figure 1b - Mounng orientaon
1)Selectamounnglocaononthewallat1.2–1.8m(4–6)above
theoorandatleast50cm(20in)fromtheadjacentwall.Do
notblockdeviceairventsfromanydireconandleaveatleast
20cm(8in)gaptootherdevices.Locatetheunitinanareawith
goodvenlaonandanaveragetemperature,whereitwillbe
responsivetochangestotheroomcondions.TheRHTshouldbe
mountedonaatsurface.
DonotlocatetheRHTwhereitcanbeaectedby:
•Directsunlight
•Drasordeadareasbehinddoors
•Radiantheatfromappliances
•Concealedpipesorchimneys
•Outsidewallsorunheated/uncooledareas
2)Usethedeviceasatemplateandmarkthescrewholes.
3)Mountthewallplatewithscrews.
•Incorrectinstallaonmaycauseashiintemperatureoutput
•Securethelidwithalockingscrew,iftherelayisconnectedtothe
mainspower.
Copyright HK Instruments 2022 www.hkinstruments. Installaon version 8.0 2022
CAUTION!
•ForCEcompliance,aproperlygroundedshieldingcableis
required.
•Usecopperwireonly.Insulateorwirenutallunusedleads.
•Supplyaseparatecableforrelayandsignaloutwhenusingline
voltagetopowertherelay.
•Anywiringmaycarrythefulloperanglinevoltagecurrentbased
oneldinstallaon.Thecoverlockingscrewmustbeinstalledif
thelinevoltageissuppliedtotherelay.
•Careshouldbeusedtoavoidelectrostacdischargetothedevice.
•Thisunithasconguraonjumpers.Youmayneedtorecongure
thisdeviceforyourapplicaon.
1)Routethecablesthroughthesquareopeninginthebackplateor
forsurfacewiringselectaknockoutonthetoporboomofthe
wallplate,asshowninFigure2a.
2)ConnectthewiresasshowninFigure2band2c.
STEP 3: CONFIGURATION
WIRING DIAGRAMS CONTINUED
ConguraonoftheRHTseriesdeviceconsistsof:
1)Conguringthejumpers(seestep4).
2)Conguraonmenuopons.(Display-andModbusversions
only.Seetheusermanualforfurtherdetails.)
Figure 2a - Roung the cables
24 V
GND
Max
rH
Temp
+
Output 0/2–10 V / 4–20 mA
Output 0/2–10 V / 4–20 mA
Output 0/2–10 V / 4–20 mA
Figure 2b - Wiring diagram: Power input & signal output
Wires can be routed through the square opening in the back plate
Wires can be routed through the top knockouts
Wires can be routed through the boom knockouts
NC
COM
NO
STEP 2: WIRING DIAGRAMS
Figure 2d - Wiring diagram: Relay
24 V
GND
Max
rH
+
Temp
V V V
Output 0/2...10 V
Output 0/2...10 V
Output 0/2...10 V
Figure 2c - Wiring diagram: Extra GND wire
NOTE!Whenusinglongconneconwiresitmaybenecessaryto
useaseparateGNDwireforvoltageoutputcurrenttoprevent
measurementdistoron.TheneedforanextraGNDwiredepends
onthecrossseconandlengthoftheusedconneconwires.Iflong
and/orsmallcrossseconwiresareused,supplycurrentandwire
resistancemaygenerateavoltagedropinthecommonGNDwire
resulnginadistortedoutputmeasurement.
Copyright HK Instruments 2022 www.hkinstruments. Installaon version 8.0 2022
1)Conguraonoftheoutputmodesof:
•Maxvalue
•Relavehumidity(rH)
•Temperature(Temp)
Selecttheoutputmode,current(4–20mA)orvoltage(0–10V),
byinstallingjumpersasshowninFigure4.Eachoutputarecongured
separately.
Toselect2–10Voutputmodeonadisplayversiondevice:
First,select0–10Voutputbyjumper(s),thenchangethevoltage(V)
outputfrom0–10Vto2–10Vviatheconguraonmenu.Please
seetheusermanualformoredetails.
Thesellerisobligatedtoprovideawarrantyofveyearsforthedeliv-
eredgoodsregardingmaterialandmanufacturing.Thewarrantyperiod
isconsideredtostartonthedeliverydateoftheproduct.Ifadefect
inrawmaterialsoraproduconawisfound,thesellerisobligated,
whentheproductissenttothesellerwithoutdelayorbeforeexpira-
onofthewarranty,toamendthemistakeathis/herdiscreoneither
by repairing the defecve product or by delivering free of charge to
thebuyeranewawlessproductandsendingittothebuyer.Delivery
costsfortherepairunderwarrantywillbepaidbythebuyerandthe
return costs by the seller. The warranty does not comprise damages
causedbyaccident,lightning,oodorothernaturalphenomenon,nor-
malwearandtear,improperorcarelesshandling,abnormaluse,over-
loading,improperstorage,incorrectcareorreconstrucon,orchanges
and installaon worknotdonebytheseller. The seleconofmateri-
alsfordevicespronetocorrosionisthebuyer’sresponsibility,unless
otherwise is legally agreed upon. Should the manufacturer alter the
structureofthedevice,thesellerisnotobligatedtomakecomparable
changestodevicesalreadypurchased.Appealingforwarrantyrequires
thatthebuyerhascorrectlyfullledhis/herduesarisenfromthede-
liveryandstatedinthecontract.Thesellerwillgiveanewwarrantyfor
goodsthathavebeenreplacedorrepairedwithinthewarranty,how-
everonlytotheexpiraonoftheoriginalproduct’swarrantyme.The
warrantyincludestherepairofadefecvepartordevice,orifneeded,
anewpartordevice,butnotinstallaonorexchangecosts.Underno
circumstanceisthesellerliablefordamagescompensaonforindirect
damage.
2)Lockingthedisplay:
Installthejumpertolockthedisplaytopreventaccesstothecongu-
raonmenuaerinstallaoniscompleted(seetheschemacsforthe
locaonofthepins).
Jumper installed to the le side pins:
0–10 V output selected
Max value
rH
Temp
0–10 V 4–20 mA
Jumper installed to the right side pins:
4–20 mA output selected
Max value
rH
Temp
0–10 V 4–20 mA
First jumper installed to the le side pins:
0-10 V output selected for Max value
Second jumper installed to the right side pins:
4–20 mA output selected for rH
Third jumper installed to the le side pins
0–10 V output selected for temperature
Max value
rH
Temp
0–10 V 4–20 mA
Figure 4
STEP 4: Jumper settings
WARRANTY POLICY
RECYCLING/DISPOSAL
The parts le over from installaon should be
recycled according to your local instrucons.
Decommissioned devices should be taken to a
recyclingsitethatspecializesinelectronicwaste.
(Grey colour indicates that a jumper is installed)
No jumper
Circuit open
Jumper installed
Circuit closed
Jumper stored
Figure 3 - Jumper installaon
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