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Dr.
Vytenis (Vyto) Babrauskas
About
the Tutor:
Dr Babrauskas was the first person to ever
receive a Ph.D. degree in Fire Protection
Engineering. He headed the fire test method
development programs at NIST for 16 years
before becoming a consultant.
Vyto has taught graduate-level engineering
courses at the University of British Columbia
and at Worcester Polytechnic Institute, has
given hundreds of lectures and presentations
and is the author of over 250 papers on fire
safety. He is the Author of the authorative
Ignition Handbook and Heat Release in Fire,
he is also the U.S. editor for Fire Safety
Journal.
In
recent years, he has been regularly teaching
classes to fire investigators on fire science
principles.
Further details from http://www.doctorfire.com
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DAY
1
Part I – General principles pertinent
to electrical fires
•
What is an electrical fire?
• Statistics on electrical fires
• Fundamentals: Ohm’s Law,
sine waves, simple circuits, energy-storing
components (inductors, capacitors)
• Energy sources: Static electricity,
electric current
• Electrical discharges (all types,
applicable both to static electricity
and electric current) |
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•
Breakdown phenomena |
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•
Paschen’s Law (air) |
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•
Dielectric strength of solid insulators |
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•
Definitions of arc and spark |
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•
Spark ignition of flammable atmospheres |
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•
Types of discharges under steady-state
conditions (i.e., with electric current
flow, not for static electricity) |
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Ignition modes involving electric current
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•
Sparking or arcing in the gas phase |
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•
Arcing across a carbonized path |
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•
Glowing and other forms of overheating
(ohmic heating |
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•
Ejection of hot particles |
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•
Miscellaneous phenomena |
•
Time for fire to initiate from a defect
• Static electricity |
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•General
principles (charge separation, accumulation,
discharge) |
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•Means
whereby charge separation occurs |
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•Types of discharges |
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•Electrostatic
charging and discharging of solids/
persons and apparel/ granular materials/
liquids |
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Lightning |
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•Electrical
characteristics |
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•Ignition
from lightning |
•
Other atmospheric discharges (St. Elmo’s
fire, ball lightning)
• Electromagnetic waves and particulate
radiation |
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•Radio
transmitters, eddy currents, dielectric
heating |
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Minimum energy requirements for ignition |
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•Gases/
Dust clouds/ Liquids/ Solids |
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Are there minimum values of voltage,
current, or power that must be exceeded
for ignition to be possible? |
DAY
2
Part II – Practical applications and
failures of devices
Back to top
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Problems with wiring devices |
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•Wiring
in 120 and 240 VAC branch circuits |
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•Electric
outlets, plugs, and connections |
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•Busbars,
switchboards, panelboards |
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•Insulated
distribution cables |
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•Service
drops, high-current-capacity conduits |
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•Branch-circuit
wiring conduits |
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•High-voltage
insulators |
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•Power
and distribution transformers |
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•Wiring
in motor vehicles |
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•Wiring
in aircraft |
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Problems with other appliances or devices
(not wiring devices) |
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•Flammability
of cabinets of electric or electronic
appliances |
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•High-limit
switches and thermostats |
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•Electric
batteries |
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•Electric
blankets, mattress pads, heating pads |
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•Heat
tapes and heat cables |
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•Electric
heaters |
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•Electric
cooking appliances |
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•Electric water heaters |
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•Electric
dryers and washers |
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•Electric
lamps and lighting fixtures |
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•Electronic
devices |
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•Computer
equipment |
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•Televisions |
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•Radio
and audio equipment |
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•Cellular
telephones |
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•Surge
suppression devices |
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Protective devices |
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•Over-current
devices (circuit breakers, fuses) |
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•Ground-fault
circuit interruption devices (GFCIs) |
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•Arc-fault
circuit interruption devices (AFCIs) |
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•Explosionproof
or intrinsically safe equipment |
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Arc beads—cause or victim? |
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Time for fire to develop from defect |
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Research status concerning electrical
fires |
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•Most
work has been done in Japan; almost
no ongoing •research in the US |
Comments,
Open Discussion |
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to top
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