automatic safety switch

基本解释

Automatic shows error, safety shield; safety switch.
自动显示故障报警，安全防护门，安全开关。
blog.china.alibaba.com
The utility model discloses a fixed quantity power supply automatic safety switch device which is suitable for the fixed quantity power supply of a room.
本实用新型公开了一种定量供电自动保险开关装置。
ip.com
As the mechanical switch has no function of automatic locking and returning to zero in power failure, there exists some potential danger when used in places where safety is called for.
机械式电源开关不具备停电自锁和断电回零等功能，在一些特殊的安全要求较高的场所，使用这种开关也存在着一定的安全隐患。