{"data":{"id":"us/30-cfr-57.6403","jurisdiction":"us","citation":"30 CFR 57.6403","heading":"Branch circuits.","body":"(a) If electric blasting includes the use of branch circuits, each branch shall be equipped with a safety switch or equivalent method to isolate the circuits to be used.\n(b) At least one safety switch or equivalent method of protection shall be located outside the blast area and shall be in the open position until persons are withdrawn.","path":["Title 30—Mineral Resources","CHAPTER I—MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR","SUBCHAPTER K—METAL AND NONMETAL MINE SAFETY AND HEALTH","PART 57—SAFETY AND HEALTH STANDARDS—UNDERGROUND METAL AND NONMETAL MINES","Subpart E—Explosives"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-30.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:25:24Z","sha256":"426f0c40f95c9476ae6a21b7cc6aee735d464650c9f7adfcdc42676f130b7e9b","source_id":"us-cfr","stale":true,"prev":"us/30-cfr-57.6402","next":"us/30-cfr-57.6404"},"notice":"GroundRules: Original legal text. Not legal advice."}