接地故障产生的电弧是引起建筑电气火灾的主要原因,RCD是预防接地故障性火灾的有效保护电器。从RCD额定剩余动作电流值的选择、上下级RCD之间的配合、RCD的极数等方面叙述了在设计中如何正确选用RCD,并结合实践说明RCD的应用。 The arc caused by a ground fault is the main cause of electrical fire in the building. The RCD is an effective protective device against earth-fault fires. From the RCD rated residual current value of the choice, the upper and lower RCD coordination, the number of poles and other aspects of RCD described in the design of the right choice of RCD, combined with practical application of RCD.