A Monitor Unit for Automatically Logging Power Line Disturbances

A portable monitor system has been developed for automatically gathering data on the quality of electrical mains supplies. The equipment will store the number of times overvoltages or underclass occur in a chosen period, and will give a breakdown of the data into five disturbance-duration categories, plus an indication of the accumulated disturbance time. The equipment is self-contained and requires no attention during the monitoring period, making it particularly useful for remote or unmanned sites. Up to 100, 000 excursions outside the preset thresholds can be tallied in any one period. The unit will continue to acquire and store data through extended mains failures for virtually the shelf life of its internal battery.