什么是保护接地？
["\u5728\u7535\u6e90\u8bbe\u5907\u4e2d\uff0c\u5c06\u4e0e\u5e26\u7535\u90e8\u5206\u7edd\u7f18\u7684\u91d1\u5c5e\u5916\u58f3\u63a5\u5730\uff0c\u4ece\u800c\u9632\u6b62\u56e0\u7edd\u7f18\u635f\u574f\u800c\u4f7f\u4eba\u89e6\u7535\uff0c\u8fd9\u79cd\u4fdd\u62a4\u63aa\u65bd\uff0c\u79f0\u4e3a\u4fdd\u62a4\u63a5\u5730\u3002"]