Chapter 5:
Loading and Firing of Fireworks
5.4
Electrical Firing
- Electrical firing allows
fireworks operators to work at a distance from the articles being fired, and is therefore,
safer for operators than manual firing.
- Electrical firing and manual
firing offer the public approximately the same level of safety.
- Electrical firing units or
controllers vary widely in complexity from simple probe-firing panels (nail boards) to
computer-driven units synchronized to music.
5.4.1
Electrical Firing Hazards
Electric matches used in conjunction with
firing cables are subject to accidental firing by electrostatic discharges, stray
currents, radio frequency energy and electrical storms.
- Radio frequency energy.
Don't use portable communications devices such as radios, cellular telephones, etc. if you
are within 4 meters (15 feet) of electric matches and electrically fired fireworks.
Don't carry these devices if you are handling fireworks with an electrical match.
- Electrical Storms.
At the approach of an electrical storm, all personnel must evacuate the display site to
the perimeter of the danger zone and return all loose articles to storage.
5.4.2
Clear Line of Sight
Position the electric firing unit so that
there is a clear line of sight to the ramps and all fireworks being electrically fired.
5.4.3
Electrical Firing Unit and Accessories
- Inspect the electrical
firing unit, cables, junction boxes and testing equipment before the display. Make
sure everything works and works together.
- Check to see that the power
sources, either batteries or commercial direct power, have sufficient power to fire all
the fireworks primed with electric matches (two 12-volt batteries in series are
recommended).
- Firing units must be
provided with at least a two-step positive interlock which ensures the panel cannot fire
unless both steps are done to prevent actions or conditions that would lead to hazardous
conditions in the field. The crew member who is firing the display is responsible
for any physical keying device at all times.
5.4.4
Electric Matches
- When using electric matches,
all fireworks must be primed with the electric matches at the display site. Shells
must be in their respective mortars and other set pieces at their intended firing
position.
- Attach the electric matches
to the fireworks by inserting the electric match into the quickmatch fuse of the article
and secure it into position so it cannot pull out of the quickmatch. Direct
insertion of the electric match into the lift charge of the shell is prohibited on the
display site.
- Never reload
mortars in an electrically fired display.
5.4.5
Steps for the Setting Up of an Electrically Fired Display
- The fireworks article must be
in the mortar, or intended firing position for articles other than shells, prior to the
attachment of the electric match.
- Lay the firing wires or
cables from the fireworks to the firing point, keeping both ends of the wire shunted until
ready to make the connection to the firing unit or battery. Ensure that no wire
comes in contact with the battery or the firing unit (the wires should be identified or
marked in accordance with the firing plan or layout of the display).
- Connect all the electric
matches to the firing wires or cables. Do not connect the wire to the firing unit
until ready for testing if there is an integral tester in the firing unit.
5.4.6
Testing and Repair
- While testing takes place, no one is allowed on the ramps.
- Using on ohmmeter, a stand
alone continuity tester or the built-in tester from the firing unit, verify the integrity
of the electrical circuit. Note that the firing unit test circuit must be current
limited to 20% of no-fire current (as specified by the manufacturer) of electric matches
being used.
- Before proceeding to the
ramp for inspection or repair, the firing unit must have been switched off, and any
physical key removed.
- If testing detects a fault,
the Supervisor in Charge or crew member will visually inspect any cables, connections,
splices or electric matches that appear defective and make the necessary repairs.
- Electrical faults can be
detected by testing isolated sections of the electrical circuit and by testing individual
wires or the electric match with intrinsically safe continuity tester or ohmmeter until
the fault is detected. Replace defective electrical matches or wires where the test
indicates a fault of discontinuity.
5.4.7
Final Connection to the Firing Unit
- Once all circuits have been
tested and are operational, connect the cables or wires to the firing unit. If the
testing is done by the firing panel, ensure full power is not applied during the testing
period (use test mode).
- The crew member responsible
for firing the display must have control of any physical keying device at all times.
- Before arming the firing
unit for actual firing, the Supervisor in Charge must confirm that the display site
perimeter is cleared of all unauthorized personnel.
5.4.8
Post-Display
Before beginning any clean-up or other work
at the site:
- Ensure that the power source
available from the firing system has been disconnected (ie. All field modules have been
discharged).
- Remove any physical keys
from the controller.
- Disconnect all cabling
starting at the power source.
5.4.9
Firing Using Batteries (Without Firing Unit)
When a battery is used, insulate the
positive terminal with insulators to prevent accidental contact with the firing
cables. Keep the battery in a covered box until time to fire.
- Don't remove the insulators
from the terminals until the danger area has been cleared of all unnecessary personnel.
- To fire, apply the ends of
the wires leading to the fireworks to the positive and negative terminals of the batteries
starting with the ground terminal (negative).
