PURPOSE: To improve decision accuracy by measuring a DC component and a dielectric tangent together in a hot-wire state, and combining both measured values for total decision.
CONSTITUTION: A switch 12A is turned off in the hot-wire state and a DC component measurement part 13 measures the DC component. A switch 12B is turned on in the hot-wire state and an dielectric tangent measurement part 14 measures the dielectric tangent. Those measurement data are sent to a control and arithmetic part 15 to perform a total decision on insulation deterioration and print out the result. In this case, the total decision results A, B, and C are obtained according to the DC component and tanδ and their combined value. Namely, A indicates an excellent insulation state, B shows that insulation characteristics tend to deteriorate and careful maintenance is required, and C indicates a defective cable which needs to be replaced immediately. Consequently, the decision accuracy is improved greatly as compared with a conventional DC component method in the hot-wire state.
ISHIHARA KAZUAKI
ABE TAKESHI
KATSUYAMA YOSHIHISA
EBINUMA YASUMITSU
FUJIWARA YASUTAKA
MINAMI MASAKI
SHOWA ELECTRIC WIRE & CABLE CO
| JPS629277A | 1987-01-17 |