Abstract
| The ability of the circuit breakers to interrupt the electrical current in circuits with capacitive load it is tested and verified in testing laboratories. During the test, the capacitive type of load impedance simulates an overhead line or an underground cable that works with no load impedance. The transient behaviour which appears at the opening of electric circuits having capacitive load impedance can determine the appearance of some dangerous over-voltages for line, cables and equipments. After testing, at the circuit interruption, it is possible to be residual electrical charge on capacitors. This endangers the lives of people who configures the test scheme. The paper describes a device that monitors the voltage on the capacitors that are connected to busbars and which alerts the staff about the presence of electric charges remaining at the end of the test. A referral unit is mounted near the bars to that are connected capacitors, while warning unit is mounted in the place where can be observed by personnel that configure the test schemes. Two variants of the device are presented. The results, obtained with the device during carrying out tests, both in the laboratory and in operation, are presented into the final section of the paper. |
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