Oklahoma Administrative Code › Title 460 - Department of Mines › Chapter 25 - Oklahoma Explosives and Blasting Rules and Regulations › Subchapter 13 - Performance Standards › Section 460:25-13-9 - Initiation of explosive charges-electric blasting

Current through Vol. 41, No. 20, July 1, 2024
(a) Electric blasting caps shall not be used
				when sources of extraneous electricity make the use of electric blasting caps
				dangerous; the blaster must chose a non-electric system.
(b) Blasting cap leg wires shall be kept
				short-circuited (shunted) until they are connected into the circuit for
				firing.
(c) Before adopting any
				system of electrical firing, the blaster shall conduct a thorough survey for
				extraneous currents, and all dangerous currents shall be eliminated before any
				holes are loaded.
(d) In any single
				blast using electric blasting caps, all caps shall be of the same style or
				function, and the same manufacture.
(e) Electric blasting shall be carried out by
				using blasting circuits or power circuits in accordance with the electric
				blasting cap manufacturer's recommendations, or an approved contractor or his
				designated representative.
(f) When
				firing a circuit of electric blasting caps, care must be exercised to ensure
				that an adequate quantity of delivered current is available, in accordance with
				the manufacturer's recommendation.
(g) Connecting wires and lead wires shall be
				insulated single solid wires of sufficient currentcarrying capacity.
(h) Bus wires shall be solid single wires of
				sufficient current-carrying capacity.
(i) When firing electrically, the insulation
				on all firing lines shall be adequate and in good condition.
(j) A power circuit used for firing electric
				blasting caps shall not be grounded.
(k) In underground operations there shall be
				a "lightning" gap of at least 5 feet in the firing system ahead of the main
				firing switch; that is, between this switch and the source of power. This gap
				shall be bridged by a flexible jumper cord just before firing the
				blast.
(l) When firing from a power
				circuit, the firing switch shall be locked in the open or "Off" position at all
				times, except when firing. It shall be so designed that the firing lines to the
				cap circuit are automatically short-circuited when the switch is on the "Off"
				position. Keys to this shall be entrusted only to the blaster.
(m) Blasting machines shall be in good
				condition and the efficiency of the machine shall be tested annually to make
				certain that it can deliver power at its rated capacity.
(n) When firing with blasting machines, the
				connections shall be made as recommended by the manufacturer of the electric
				blasting caps used.
(o) The number
				of electric blasting caps or circuits connected to a blasting machine shall not
				be in excess of its rated capacity. Furthermore, in primary blasting, a series
				circuit shall contain no more caps than the limit recommended by the
				manufacturer of the electric blasting caps in use.
(p) The blaster shall be in charge of the
				blasting machines, and no other person shall connect the leading wires to the
				machine.
(q) Blasters, when testing
				circuits to charged holes, shall use instruments designed solely for blasting
				such as Blasters ohmmeter, Blasters Multimeter, or Blasters
				galvanometer.
(r) Whenever the
				possibility exists that a leading line or blasting wire might be thrown over a
				live power line by the force of explosion, care shall be taken to see that the
				total length of wires are kept too short to hit the lines, or that the wires
				are securely anchored to the ground. If neither of the requirements can be
				satisfied, a nonelectric system shall be used.
(s) In electrical firing, only the blaster
				making leading wire final connections shall fire the shot. All connections
				shall be made in sequence from the bore hole back to the source of firing
				current, and the leading wires shall remain shorted and not be connected to the
				blasting machine or other source of current until the charge is to be
				fired.
(t) After firing an electric
				blast from a blasting machine, the leading wires shall be immediately
				disconnected from the machine and short-circuited. The leading wires should be
				tested immediately so defects caused by flyrock can be repaired before the next
				blast.
Added at 13 Ok Reg 1111,
				  eff 1-11-96 (emergency); Added at 13 Ok Reg 3499, eff
				  8-26-96