This paper describes that even after cut off the power supply the capacitors still stored charge

so

the capacitor should be in good time discharge

not only to physical security needs

but also to reduce the capacitor residual voltage so as to regular repetitive switching in

the national standard has stipulated requirements for capacitor discharge.The paper also describes the reasons and necessity of fitting rapid discharger under five circumstances

introduces two type of domestic dischargers and a portable device for measuring capacitor discharge performance.