8000 Zone2.pdf

MTL8000-2/x Series - OverviewMTL8000 with generalpurpose field wiringMany industry applications do not presentan explosion risk from gas or dust hazards.In others, the environment may be classifiedas a Zone 2 or Division 2 hazardous area,where flammable material is expected tooccur only in abnormal conditions. For bothof these the 2/2 system provides effectivedistributed I/O for process control.MTL8000 supports a full range of I/O moduletypes covering inputs and outputs forboth analog and discrete circuits. The nodecan be mounted out on the plant in a suitableenclosure providing protection againstthe environment. Figure 3 shows a nodecontaining all the key components: a BusInterface Module, PSU modules (including aredundant one), I/O modules on carriersand a pair of carrier-extenders linked withan extension cable.local18–36 V DCpowerSystem powersupplyOtional redundantsystem powersupply moduleCarrierextender(LH)Bus InterfaceModule4-module carrier(General purpose p orZone 2/Div 2)(General purpose p orZone 2/Div 2)Bussed Field PowerBussed Field Power8-module carrier(General purpose p orZone 2/Div 2)(General purpose p orZone 2/Div 2)Carrierextender(RH)To maximum of 32I/O modulesD.C. power linkto otherextenderMTL8000 with intrinsicsafety field wiringThe MTL8000 Process I/O System is capableof supporting I/O modules with intrinsicsafety (IS) field wiring, for connection tocertified or ‘simple apparatus’ field devicesin Division 1 or Zone 0 hazardous areas(see Figure 4). A range of I/O module typeswith IS field circuits for industrystandardDI, DO, AI and AO applications issupported.I/O modules with built-inprotectionAll voltage and current-limiting componentsrequired for IS protection are incorporatedwithin the I/O module housings, so noexternal, add-on zener barriers or galvanicisolators are necessary. IS field terminalsare distinguished from other types by bluecolouring of the terminal housing. A uniqueand sophisticated mechanical keyingmechanism prevents modules with differentprotection techniques from being interchanged,so that potentially explosive ordamaging conditions cannot occur.Integrated power suppliesPower for IS I/O modules is derived fromintegrated, modular power supply units.Each power unit is capable of supplyingbetween eight and twenty I/O modules,depending on the I/O type and mix.Optional power supply redundancy issupported by means of an additional,redundant supply unit connected in an‘n+1’ arrangement. In applications withmixed IS and non-IS field wiring, the fullfacilities of the ‘Bussed Field Power’ regimeare retained for the non-IS part of the system.Figure 3 MTL8000 nodeLocal12 V dcpowerBIMCarrierCarrier(LH)BusInterfaceModuleLANterminalsRailbus IsolatorModule andCarrierLocal18–36V dcpower4-module carrier(IS field wiring)[EEx ia]I/O modulepower supplyLocal18–36V dcI/O modulepower supply8-module carrier (IS field wiring)[EEx ia]8-module carrier(IS field wiring)[EEx ia]Figure 4 MTL8000 node with IS field wiringIn nodes populated only with IS I/Omodules, a separate system power supplymodule provides power for the Bus InterfaceModule and ‘node services’. Redundancyof this supply is also supported.CarrierExtender(RH)DINrailExtendercablesLocal18–36V dcpowerTo maximum of32 I/O modulesOptional n+1redundantI/Omodule powersuppl yMTL Power Court, Luton, Bedfordshire, England LU1 3JJTel: +44 (0)1582 723633 Fax +44 (0)1582 422283E-mail: enquiry@mtl-inst.com Web site: http://www.process-io.comSept 2002