Circuit arrangement for metrological monitoring of the serviceability of resistive heating elements

摘要

The field of application of the invention relates to the monitoring of the serviceability of resistive heating elements combined into a plurality of heating zones in technological complexes for plastics processing. The monitoring of the resistive heating elements is carried out by monitoring the current of the phases of the three-phase supply with the aid of current transformers and A/D converters, the resistive heating elements being connected into the supply in groups, by means of a sequence control system, to one resistive heating element respectively per phase, according to the monitoring requirement. The fault analysis is carried out by checking the actual values measured by the current transformers and the subsequent A/D converter against the desired values stored in the sequence control system. Automatic, exact fault analysis is possible at low device cost by means of the solution according to the invention. <IMAGE>