GERMANY: 1. SprengV Amendment 1

Blasting machines

• mechanical requirements
  • The blasting machine must work reliably
  • The blasting machine must have a robust and closed enclosure
  • All parts of the blasting machine must be undetectable
  • The design must complicate unauthorized operation
• electrical requirements
  • The blasting machine must have massive connection terminals. They must not be hollow and the diameter must be a minimum of 4mm. Protection against touching electric shock must be given.
  • Between the terminals there must be an isolation barrier that overtops the connection surface for at least 8mm.
  • Isolation between electrical parts and the housing must be at least 1000V or the double working voltage.
  • Isolation parts must comply with the state of the art
  • Capacitor blasting machines have to ensure that the capacitor is discharged after blasting.
  • An interlock must ensure that triggering is only possible if the full electrical power (energy) is available.
• performance
  • type A
    • After 1ms the current must reach at least 1A. From the beginning until falling below 1A, the impulse must be at least 4mWs/Ω.
    • limiting resistance

      10 ignitors	60Ω
      20 ignitors	110Ω
      30 ignitors	160Ω
      50 ignitors	260Ω
      80 ignitors	410Ω
      100 ignitors	510Ω
      160 ignitors	810Ω
      200 ignitors	1010Ω

  • type U
    • After 1ms the current must reach at least 2A. From the beginning until falling below 1.5A, the impulse must be at least 18mWs/Ω.
    • limiting resistance

      10 ignitors	55Ω
      20 ignitors	90Ω
      30 ignitors	125Ω
      50 ignitors	195Ω
      80 ignitors	300Ω
      100 ignitors	370Ω
      160 ignitors	580Ω
      200 ignitors	720Ω

  • type HU
    • After 1ms the current must reach at least 30A. From the beginning until falling below 15A, the impulse must be at least 3.3Ws/Ω.
    • limiting resistance

      20 ignitors	15Ω
      80 ignitors	50Ω
      160 ignitors	100Ω

• other requirements
  • In regard to protection against firedamp the blasting machines must comply to the state of the art.
  • The ignition current pulse must not be longer than 4ms. After triggering the recharging of the capacitor, triggering a second pulse must be impossible.

Blasting circuit continuity tester

• general requirements
  • The current source must not be accessible
  • The voltage of the current source must be lower equal 12V
  • The test current must be less than 25mA
  • There must be protection resistors to limit the current in a single failure case to 50mA
• special requirements for Ω–meters
  • The accuracy must be 1.5% of the full range
  • The zero point should be regulated
  • A 10% deviation of the current source voltage must not influence the measurement accuracy

AUSTRIA: Regulation for blasting for mining

Very similar to the GERMAN version.

• Between the terminals there must be an isolation barrier that overtops the connection surface for at least 8 10mm.
• A performance sheet must be on the housing
  • type description
  • manufacturer and manufacturing site
  • site number
  • manufacturing date
  • limiting resistance
  • blasting voltage and capacitor capacity

US: eCFR / Title 30 / Chapter 1 / Subchapter K / Part 56 / Subpart E / Electric Blasting

• Shunting
  Except during testing —
  • Electric detonators shall be kept shunted until connected to the blasting line or wired into a blasting round;
  • Wired rounds shall be kept shunted until connected to the blasting line; and
  • Blasting lines shall be kept shunted until immediately before blasting.
• Firing devices
  • Power sources shall be capable of delivering sufficient current to energize all electric detonators to be fired with the type of circuits used. Storage or dry cell batteries are not permitted as power sources.
  • Blasting machines shall be tested, repaired, and maintained in accordance with manufacturer's instructions.
  • Only the blaster shall have the key or other control to an electrical firing device.
• Circuit Testing
  A blasting galvanometer or other instrument designed for testing blasting circuits shall be used to test each of the following:
  • Continuity of each electric or electronic detonator in the blasthole prior to stemming and connection to the blasting line.
  • Resistance of individual series or the resistance of multiple balanced series to be connected in parallel prior to their connection to the blasting line.
  • Continuity of blasting lines prior to the connection of electric or electronic detonator series.
  • Total blasting circuit resistance prior to connection to the power source.