Mechatronic temperature measurement Bimetal temperature switch Model TFS35 WIKAdatasheetTV35.01 Applications Mobilehydraulics Machinebuilding Compressors Motors Coolingandheatingcircuits Special features Fixedswitchingtemperature Current-independentswitching Automaticreset Noadditionalvoltagesupply Bimetal temperature switch, model TFS35 Simpleandfastmounting Description Temperatureswitchesaregenerallyusedinindustr yforTheresetswitchingtemperatureistypically3015K...below limitingtemperatureThe. ymonitorthetemperatureof theswitchingtemperature. machiner yandequipmentand,forexample,switchoff machiner yifitoverheatsorswitchonafantocoolContact designthe equipment. ThemodelTFS35bimetaltemperatureswitchcanbe deliveredintwocontactdesigns. Function ANormallyClosed(NC=closedinthenormalstate)opens BimetalsformthebasisofWIKAtheTF S35temperature acircuitandshutsdownthemachiner y. switches.Temperaturesensingiscarriedoutbyabimetal disc,whichsnapsoverwhenthenominalswitching ANormallyOpen(NO=openinthenormalstate)closesa temperature(NST)isreached. circuitonreachingtheswitchingtemperature,inorderthat, forexample,afanorwarninglampcanbeswitchedon. Oncoolingbackdowntotheresetswitchingtemperature (RST),theswitchreturnstoitsoriginal state. Inbothcases,oncoolingdownbelowtheresetswitching temperature,thecontactsreturntotheiroriginalstate,sothat ThebimetaldiscintheTFmodelS35bimetaltemperature themonitoredequipmentcanagainworknormally. switchcarr ysnocurrent,andthiseliminatesthepossibilityof arcing. Withcurrent-carr yingbimetaldiscsthereisalsoadangerof prematureswitchingasaresultofhigherself-heating. WIKAdatasheetTV35.0111/2012 Page1of4Max. switching voltage Thermowell Resistiveload(cos=1): Material AC48V,3A Brass DC24V,3A Stainlesssteel DC12V,4A Stem diameter D 10mm Threadsize(versionwithoutstem) Contact resistance Process connection <50m Mountingthread: GB GB Dielectric strength GB M14x1.5 AC1,500V,50Hz M22x1.5 betweenelectricalconnectionsandhousing NPT Othersonrequest Temperature ranges Insertion length U 30mm NominalSwitchingTemperature(NST) 40mm 50...200C 50mm Note: Threadlength(versionwithoutstem) Thenominalswitchingtemperaturecanbeselected Othersonrequest instepsof5ItK.ispresetondeliver yandcannotbe changed. Response time Switchpointaccuracy 5K Theresponsetimeissronglyinfluencedby thethermowellused(diameter,material) ResetSwitchingTemperature(RST) theheattransferfromthermowelltotheswitchingelement Theresetswitchingtemperatureinbimetaltemperature theflow-rateofthemedium switchesistypically1530...Kbelowtheswitching temperature. DuetothedesignoftheTFmodelS35bimetaltemperature Toensureasaferesetoftheswitchatlowswitching switch,thereisoptimumheattransferfromthemediumtothe temperatures,caremustbetakenthatthetemperature switchingelement. differencebetweenthemeasuringpointandambientis highenough sinceother wisetheswitchcannotcoolback downtotheresetswitchingtemperatureandthusthe Vibration resistance equipmentwillnotbeabletoreturntoitsnormalstate. Duetothespecificassemblyoftheswitchingelements Ambienttemperature used,thevibrationresistanceoftheTFmodelS35bimetal -50...+125C temperatureswitchisver yhigh. Note: Dependingonthemountingsituation,themedium, Withsmallinser tionlengthsthereisapossibilitythatthe temperatureandinser tionlength,thevibrationresistanceis temperatureattheconnectorcanreachimpermissibly upto10g. highvaluesThis. absolutelymustbetakenintoaccountin thedesignofthemeasuringpoint. Shock resistance Upto100g,dependingonthemountingsituation,medium andtemperature Page2of4 WIKAdatasheetTV35.0111/2012