riser bus bar

例句：

1. 1. The elevator's riser bus bar is damaged, which makes it difficult to operate.
   电梯的升降机导轨受损，导致操作困难。
2. 2. The construction workers had to repair the riser bus bar before they could continue working on the building.
   建筑工人在继续工作之前必须修理升降机导轨。
3. 3. The riser bus bar is an essential part of the elevator system, ensuring that the elevator can move up and down smoothly.
   升降机导轨是电梯系统的重要组成部分，确保电梯能够平稳地上下移动。