Priority control for load circuit network - compares power consumption against preset level and opens contactor if level is exceeded

摘要

The priority control is for load circuit networks where power demands above a certain level must be avoided or minimised for tariff reasons etc. Power consumption is detected by a transformer with its primary in the phase line supplying both priority i.e. lightning loads and non-priority loads such as heaters which can be temporarily interrupted. The phase line is split such that a contactor can isolate the latter loads. The transformer provides a power drawn related voltage which is fed to a comparator via a rectifier and amplifier. The comparator has a preset potentiometer derived input, its output operating the contactor if the preset level is exceeded. The contactor control is via a memory and delay set at the convenience of the user, pref. about five minutes.