automatic safety switch

基本解释

Automatic shows error, safety shield; safety switch.
自動顯示故障報警，安全防護門，安全開關。
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.
本實用新型公開了一種定量供電自動保險開關裝置。
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.
機械式電源開關不具備停電自鎖和斷電廻零等功能，在一些特殊的安全要求較高的場所，使用這種開關也存在著一定的安全隱患。