New Jersey Administrative Code
Title 12 - LABOR AND WORKFORCE DEVELOPMENT
Chapter 190 - EXPLOSIVES
Subchapter 7 - USE OF EXPLOSIVES
Section 12:190-7.12 - Initiation with electric detonators

Universal Citation: NJ Admin Code 12:190-7.12

Current through Register Vol. 56, No. 18, September 16, 2024

(a) Precautions shall be taken to prevent accidental discharge of electric blasting caps from current induced by radar, radio transmitters, lightning, adjacent power lines, dust storms or other sources of extraneous electricity.

1. All blasting operations shall be suspended and all persons shall be removed from the blasting area during the approach and progress of an electric storm.

2. Signs warning against the use of mobile radio transmitters shall be posted on all roads within 350 feet of the blasting operations.

3. The blaster shall comply with Radio Frequency Radiation Hazards, IME No. 20-1978.

4. Before commencing blasting operations under high voltage electric power lines or in other areas suspected of having extraneous electric currents, the area shall be tested for extraneous electric current by a competent person using an instrument designed for this purpose. Where extraneous electric currents exceeding 0.05 ampere are found, the use of electric blasting is prohibited.

5. When electric equipment or energized power distribution circuits are within a horizontal distance of 25 feet of the blast holes, the area shall be tested for extraneous electric current by a competent person using an instrument designed for the purpose. Testing need not be performed where the possible source of extraneous electric current is removed or turned off. This provision shall not apply to overhead electric lines, when the utility company gives approval to use electric blasting caps.

6. The leg wires of the electric blasting caps shall be kept shunted unless being tested or wired into the blasting circuit.

7. The firing line shall be kept shunted until immediately prior to the time of hook-up to the blasting machine or firing switch.

(b) Where electric blasting caps are used under electric power lines, the firing line shall be weighted down to prevent the line from coming in contact with the electric power lines.

(c) Due precautions shall be taken to ensure that the electric system will function properly.

1. All electric blasting caps in a single blast shall be of the same type, same function, and of the same manufacturer.

2. Care shall be exercised to ensure that an adequate quantity of delivered current is available in accordance with the manufacturer's recommendations.

3. The insulation on all electric lines to be used shall be adequate and in good condition and kept from the contact with any electric conductor outside the electric blasting circuitry.

4. The firing line shall be a solid wire and have sufficient capacity to carry the firing current and have a current carrying capacity of not less than No. 14 American Wire Gage copper wire.

5. Electric blasting caps shall be tested for continuity after the blast hole has been loaded and before the stemming is added.

(d) Precautions shall be taken in the sequence of wiring the blasting circuitry.

1. The wiring of the blasting circuitry shall not commence until the work can proceed to completion without interruption.

2. The electric blasting cap leg wires shall be connected and tested for continuity.

3. The leg wires shall be connected to the connecting wires or bus wires and tested for continuity.

4. The connection wires shall be connected to the firing line and tested for continuity. The firing line shall be reshunted.

5. All testing shall be done by a blasting ohmmeter designed for this purpose. The ohmmeter shall be kept in good condition and be periodically tested. A malfunctioning ohmmeter shall be repaired by the manufacturer or the manufacturer's assigned representative when used for this purpose.

(e) When blasting with a blasting machine, the blasting machine shall be:

1. Designed specifically for this purpose;

2. The rated capacity needed;

3. In good working condition;

4. Tested at least once a month by procedures recommended by the manufacturer;

5. Repaired only by the manufacturer or a competent person; and

6. Protected from damage.

(f) Precautions shall be taken when firing from a power line source.

1. The firing circuitry shall not be grounded or placed where it can pick up the extraneous electric current.

2. The firing circuitry shall be a solid wire and have sufficient capacity to carry the firing current and have a capacity of not less than No. 14 American Wire Gage copper wire.

3. The insulation on all firing lines shall be in good condition.

4. When in a tunnel or other narrow passage, the firing line shall be placed on insulators on the wall opposite other electric power lines.

5. There shall be a safety switch on each branch firing line.

6. The main permanent firing line shall be arranged to have a safety switch, at least a five foot lightning gap, and a power switch.

7. All switches for power circuits shall be the proper capacity, enclosed, capable of being locked in the "off" or "open" position, and be distinctively labeled.

8. The power source shall not exceed 550 volts.

9. All switches shall be kept locked unless firing a blast. The keys shall be entrusted only to the blaster.

Disclaimer: These regulations may not be the most recent version. New Jersey may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
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