| 摘要 |
PURPOSE:To satisfy the one point grounding of a communication apparatus and, further, suppress a voltage induced in a communication cable connecting the communication apparatuses and protect the communication apparatuses from external noises by a method wherein an auxiliary grounding wire is laid along the communication cable. CONSTITUTION:When a communication cable 3 which connects a plurality of communication apparatuses 5 in a building is installed in the building, one or a plurality of auxiliary grounding wires (shielded wires) 1 are laid along the communication cable 3. The more closely to the communication apparatus 5 the auxiliary grounding wire 1 is installed, the higher the effect of suppressing a voltage induced in the communication cable 3. With this constitution, the one point grounding of the communication apparatus 5 can be satisfied and, further, a voltage induced in the communication cable 3 can be suppressed and the communication apparatuses 5 can be protected from external noises such as lightning surge currents. |
