To protect electric device and control it.The protection features of fuse series electricity match with transformer,which is applicable to loop net power supply unit.

It, a kind of rotate load switch of double cracks using air SF6 as isolation and extinguishing medium,applies to the usage of power distribution system of 10kv. Every switch is permanently sealed after charging 0.4bar of the air SF6.It doesmt matter if switch is installed vertically or horizontally. The typical installation inside RMU is the way to install steel lattice between  cable chamber and bus room. This  method separate bus and cable joint ,which  matches with the strictest demands operting.

If circuit error happens that makes exaggerate current so that switch inside fires inside, there is a structural weak spot,which would be pushed and then  the gate over the switch will open to lead the air out.

Using environmental conditions ,

a.  ambient air temperature, upper limit+40, lower-15

b. daily average level   less than 35