MSHA - Code of Federal Regulations - 30 CFR 57.6404
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MSHA - Title 30 CFR
30 CFR § 57.6404
Separation of blasting circuits from power source.


(a) Switches used to connect the power source to a blasting circuit shall be locked in the open position except when closed to fire the blast.

(b) Lead wires shall not be connected to the blasting switch until the shot is ready to be fired.


[58 FR 69596, Dec. 30, 1993]