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TECHNOLOGIES

Catalogue Control Monitoring - 21326 Control & monitoring

Operation in hazardous areas There are basically two installation options:

Heating systems in hazardous areas have to meet strict safetyrequirements.As a rule,a fault in the system must never lead to dangerous overheating.It practice this means that the maximumtemperature has to be limited according to the temperatureclass,for example,by providing a thermal cut-out. Therefore,two devices are necessary for operation in hazardous areas:a temperature controller and a thermal cut-out.The temperature controller regulates the desired workingtemperature,while the thermal cut-out will switch off the heating system permanently if the specified maximum temperature is exceeded. In the case of self-limiting heating tapes,either a controller or a thermal cut-out will be sufficient,depending on thetemperature class. 1.Installation of controller/cut-out in a non-hazardous areaThis possibility is usually preferred for technical and economic reasons.The sensor circuits,which must be intrinsically safe in compliance with EExi,run into the hazardous area.2.Installation of controller/cut-out in a hazardous areaThis applies in cases where the control has to be mounted directly onthe heating system or where a non-hazardous area is not available.Please note that according to Elex V installations in hazardous areasmust be subjected to an acceptance test carried out by an authorizedinspector.
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