摘要 |
PROBLEM TO BE SOLVED: To reduce the cost of a switch gear device in which the occurrence of a dew condensation state can be detected.SOLUTION: A dew condensation detection device of a switch gear comprises a sensor 1 having a pair of comb-shaped electrodes on a surface of an insulator, a power supply 2 for applying a voltage to the sensor 1, and a leakage current detector 3 for detecting a leakage current from the sensor 1. Leakage current characteristics to humidity of the sensor 1 are preliminarily measured to define a surface resistivity showing a prescribed leakage current, as a set value, and the sensor 1 is arranged in a switch gear to detect a leakage current from the leakage current detector during operation of the switch gear. The detected leakage current is converted to a surface resistivity, and this surface resistivity is compared with the set value to determine the occurrence of a dew condensation state. |