脱扣装置 meaning in English

free trip
freehand
release
tripping device

Ac load break switches with tripping device for 3 . 3 kv or 6 . 6 kv
带脱扣装置的3 . 3kv或6 . 6kv交流负荷断路开关
Automatic release device
自动脱扣装置
Vacuum trip device
低真空脱扣装置
Reversible tripping devices , 60 v , for telecommunication equipment ; testholder and gauges for tests
电信设备用v可逆脱扣装置.试验用试验架和量规
Reversible tripping devices , 60 v , for telecommunication equipment ; technical datas and test conditions
电信设备用v可逆脱扣装置.技术数据和试验条件