| 摘要 |
PURPOSE:To directly connect main circuit side and control circuit side, and to obviate the occurrence of flashover despite long-term use by applying insulation sheath on the outside circumference bundled with optical fibers, and providing a gas dam and a blast port to one end part of this sheath. CONSTITUTION:An optical fiber cable 1 is made by bundling prescribed number of optical fibers consisting of cores, clads and protecting coverings, and a plastic covering is applied on the outside circumference thereof. A gas dam 4 is formed in one end part 3A of the covering 3 of the cable 1. A dry air blast port 5 is provided to this part 3A, so that dry air can be fed into the cable 1. Hence, the pressure in the cable 1 is always higher than the outside, and this obviates the inclusion of moisture from the outside. As a result, a decrease in dielectric strength does not occur despite direction connection of a main circuit on high voltage side and a control circuit on low voltage side by means of the optical fiber cable, hence the occurrence of accidents such as flashover is obviated. |
