30 CFR § 57.6603
Air gap.
At least a 15-foot air gap shall be provided between the blasting circuit and the electric power source.
[58 FR 69596, Dec. 30, 1993]
30 CFR § 57.6603
Air gap.
At least a 15-foot air gap shall be provided between the blasting circuit and the electric power source.
[58 FR 69596, Dec. 30, 1993]
