Kentucky Administrative Regulations › Title 805 - ENERGY AND ENVIRONMENT CABINET › Chapter 4 - Division of Explosives and Blasting › Section 805 KAR 4:110 - Initiation of explosive charges; electric blasting

Current through Register Vol. 51, No. 1, July 1, 2024
RELATES TO: KRS 351.350
NECESSITY, FUNCTION, AND CONFORMITY: KRS 351.335 requires the
				Department for Natural Resources to promulgate rules and administrative
				regulations concerning the manufacture, transportation, sale, storage, or use
				of explosives and assembled components of explosives, and the maintenance of
				such explosives which has a direct bearing on safety to life and property. This
				administrative regulation effects the provisions of that law.
Section 1.
(1) Electric blasting caps shall not be used
			 where sources of extraneous electricity make the use of electric blasting caps
			 dangerous. Blasting cap leg wires shall be kept short-circuited (shunted) until
			 they are connected into the circuit for firing.
(2) 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.
(3) In any single blast
			 using electric blasting caps, all caps shall be of the same style or function,
			 and of the same manufacture.
(4)
			 Electric blasting shall be carried out by using blasting circuits or power
			 circuits in accordance with the electric blasting cap manufacturer's
			 recommendations, or those of an approved contractor or his designated
			 representative.
(5) When firing a
			 circuit of electric blasting caps, care shall be exercised to insure that an
			 adequate quantity of delivered current is available, in accordance with the
			 manufacturer's recommendations.
(6)
			 Connecting wires and lead wires shall be insulated single solid wires of
			 sufficient current-carrying capacity. In addition, the lead wire shall be of
			 sufficient length to allow the blast to be detonated from a safe distance and
			 location.
(7) Bus wires shall be
			 solid single wires of sufficient current-carrying capacity.
(8) When firing electrically, the insulation
			 on all firing lines shall be adequate and in good condition.
(9) A power circuit used for firing electric
			 blasting caps shall not be grounded.
(10) In underground operations, when firing
			 from a power circuit, a safety switch shall be placed in the permanent firing
			 line at intervals. This switch shall be made so it can be locked only in the
			 "off" position and shall be provided with a short-circuiting arrangement of the
			 firing lines to the cap circuit.
(11) In underground operations there shall be
			 a "lightning" gap of at least five (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 immediately before firing the
			 blast.
(12) 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 in the
			 "off" position. Keys to this switch shall be entrusted only to the
			 blaster.
(13) Blasting machines
			 shall be in good condition and the efficiency of the machine shall be tested
			 periodically to make certain that it can deliver power at its rated
			 capacity.
(14) When firing with
			 blasting machines, the connections shall be made as recommended by the
			 manufacturer of the electric blasting caps used.
(15) The number of electric blasting caps
			 connected to a blasting machine shall not be in excess of its rated capacity.
			 Furthermore, a series circuit shall contain no more caps than the limits
			 recommended by the manufacturer of the electric blasting caps in use.
(16) The blaster shall be in charge of the
			 blasting machines and no other person shall connect the leading wires to the
			 machine except under the direction of the blaster.
(17) Blasters shall test all electric
			 blasting caps and electric blasting cap circuits by using only a blasting
			 galvanometer, blasting ohmmeter, or blasting multimeter, designed specifically
			 for the purpose of testing individual electric blasting caps and circuits
			 containing electric blasting caps. Such instruments shall be clearly marked as
			 being designed for such purposes, and shall be used in accordance with the
			 manufacturer's recommendations.
(18) Whenever the possibility exists that a
			 leading line or blasting wire might be thrown over a live powerline by the
			 force of an 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 these requirements can be satisfied, a
			 nonelectric system shall be used.
(19) 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.
(20) After
			 firing an electric blast from a blasting machine, the leading wires shall be
			 immediately disconnected from the machine and short-circuited.
(21) All blasting machines, other than
			 rack-bar and twist type generators, shall have a normally open firing switch
			 equipped with a spring device or other self-returning mechanism that
			 automatically returns it to the nonfiring position after the shot has been
			 detonated.
(22) Due precautions
			 shall be taken to prevent accidental discharge of electric blasting caps or
			 explosives from current induced by radar, radio transmitters, lightning,
			 adjacent powder lines, dust storms, or other sources of extraneous electricity.
			 These precautions shall include:
(a) The
			 shunting or short-circuiting of detonators in holes which have been primed
			 until wired into the blasting circuit.
(b) The suspension of all blasting operations
			 and removal of persons from the blasting area during the approach and progress
			 of an electric storm.
(c) The
			 prominent display of adequate signs, warning against the use of mobile radio
			 transmitters, on all roads within 1,000 feet of blasting operations. Whenever
			 adherence to the 1,000-foot distance would create an operational handicap, this
			 distance may be modified so long as the modification is adequately designed in
			 compliance with paragraph (e) of this subsection to prevent any premature
			 firing of electric blasting caps. Specimens of signs which satisfy these
			 requirements are as follows:
Blasting Zone
1,000-ft.
about 48" X 48"
Turn Off
2-Way Radio
about 42" X 36"
This paragraph shall not apply to surface mining
				operations.
(d) Mobile radio
			 transmitters which are less than 100 feet away from electric blasting caps in
			 other than original containers may be left "on" for receiving purposes, but may
			 only be used to transmit if in compliance with paragraph (e) of this
			 subsection.
(e) Compliance with the
			 recommendations of the Institute of Makers of Explosives with regard to
			 blasting in the vicinity of radio transmitters as stipulated in "Safety Guide
			 for the Prevention of Radio Frequency Radiation Hazards in the Use of
			 Commercial Electric Detonators," IME Publication No. 20, December 1988,
			 incorporated herein by reference. This document may be reviewed or copied at
			 the Department for Natural Resources, 300 Sower Boulevard, Frankfort, KY 40601
			 during normal business hours from 8 a.m. to 4:30 p.m.
(23) All electric blasts shall be fired with
			 an electric blasting machine or power source designed specifically for
			 detonating electric blasting caps.
(24) In parallel blasting circuits, the
			 circuit shall be wired so that the resistances in all series are
			 balanced.
(25) When blasting
			 electrically, a blasting galvanometer, blasting ohmmeter, or blasting
			 multimeter shall be used to test:
(a)
			 Resistance of individual caps, series of caps, or the resistance of multiple
			 balanced series to be connected in parallel prior to their connection to the
			 blasting line;
(b) Continuity of
			 blasting lines prior to the connection of electric blasting cap series;
			 and
(c) Total blasting circuit
			 resistance prior to connection in the power source.
(26) Immediately after the blast has been
			 fired, the firing line shall be disconnected from the blasting machine, or
			 where power switches are used, they shall be locked open or in the "off"
			 position.