The arc protection system operates very fast and the action time is kept within a few milliseconds, which is far better than the traditional bus protection. Before the pressure and temperature in the switchgear increase sharply, the tripping command of arc protection will cut off the short-circuit current in case of fault and cut off the fault in the unit room of the switchgear, so as to reduce personnel damage and equipment loss.

        When the medium voltage bus fails, the arc current and the removal time determine the degree of harm. The faster the fault is removed, the better. The damage degree caused by the internal fault of the switch cabinet depends on the arc burning time. According to relevant data, the damage to the equipment caused by different arc burning time is also different. There will be no significant damage at 35ms. Generally, it can be put into use after checking the insulation resistance, The damage is very small at 100ms. Minor repair or cleaning is required before the switch cabinet is put into operation again. The equipment damage is very serious at 500ms, which will seriously hurt the on-site personnel. The on-site operation can only be normal after the equipment is worse.

        Improving the arc withstand time of the switchgear can reduce the damage degree of the fault to a certain extent, such as improving and strengthening the structure of the switchgear, but it needs a lot of cost in this regard.

        However, it is very cost-effective to use the price of a set of electric arc protection device to protect the safe and normal operation of the switchgear and on-site staff.