relay block terminal 中継端子台

block system relay 闭塞系统继电器

Relay Automatic Block 继电器自动闭塞

unit-block type relay interlocking 组合式电气集中联锁

all-relay semiautomatic block 继电半自动闭塞

relay semiautomatic block 继电半自动闭塞

all-relay semiautomatic block system 继电半自动闭塞

all-relay semi-automatic block system 继电半自动闭塞

block relay 闭锁继电器