POWER FEEDING PATH SWITCHING CIRCUIT FOR UNDERWATER BRANCHING DEVICE AND FEEDING METHOD FOR SUBMARINE CABLE COMMUNICATION SYSTEM

摘要

PURPOSE:To execute a direct current insulated resistance test for the feeding path of the submarine cable communication system by insulating the feeding path in the underwater branching device from sea water in the state of no feeding. CONSTITUTION:First - third connecting terminals 101-103 are provided to be connected to the feeding paths of submarine cables, a first feeding path 104 is formed between the first and second connecting terminals 101 and 102 to execute feeding between both terminals, and a second feeding path 105 is formed between the third connecting terminal 103 and the ground to execute feeding at one terminal. The driving part 106L of a first relay 106 is arranged at the first feeding path 104, and a switching part 106C is arranged at the second feeding path 105. In the case of de-energizing the relay, the switch part 106C disconnects the third connecting terminal 103 from the ground and in energizing the relay, the terminal is grounded. In such a manner, all the feeding paths in the feeding path switching circuit are insulated from sea water. Thus, in the case of no feeding, the direct current insulated resistance test can be executed for the feeding path of the submarine cable.