| 摘要 |
A surge protection circuit for use in a three-phase four-wire system circuit is provided which can ensure protective measures on the load side against lightning surge and further can facilitate the connection by use of surge modules. In a surge protection circuit (1(1a)) used in a three-phase four-wire system circuit, a first three-phase three-wire surge module (10) has its respective terminals connected to a first phase (R), a second phase (S), a third phase (T) and a fifth phase (E); a single-phase two-wire surge module (20) has its respective terminals connected to one phase (R), which is one of the first phase (R), the second phase (S) and the third phase (T), a fourth phase (N) and the fifth phase (E); and a second three-phase three-wire surge module (30) has its respective terminals connected to two phases (S, T), which are the other ones of the first phase (R), the second phase (S) and the third phase (T) unconnected to the single-phase two-wire surge module (20), the fourth phase (N) and the fifth phase (E). |
