Electrical Hazards for Fire and Rescue Departments Part II: Transformer FiresGround and Substation

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Electrical Hazards for Fire and Rescue
DepartmentsPart II Transformer Fires-Ground
and Substation
Captain I Gary C. Dize Health and Safety
Division Fairfax County, Virginia
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Electrical Hazards

• Transformers

• Hazards
• High voltage (overhead underground).
• Oil-filled switch gear, transformers.
• Toxic smoke and gases due to burning oil
  insulating materials.
• Intense heat of a fire can collapse steel
  framework.
• Explosions from oil-filled equipment.
• Exploding glass porcelain insulators.
• Falling wires.

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Electrical Hazards

• In the rare case where the fire must be attacked
  and/or the equipment has not been de-energized,
  exercise extreme caution.
• Establish a safety zone, deny access, and
  evacuate area as needed.
• If the equipment is still energized, little can
  be done to extinguish the fire, as the oil will
  continue to re-ignite.

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Electrical Hazards

• Some equipment, such as circuit switches and
  breakers, have porcelain housings that are
  pressurized. When involved in the fire and
  sprayed with water, the sudden temperature change
  may result in a violent explosion.
• Any electrical apparatus, transformer, or switch
  that has been on fire cannot be salvaged. If the
  fire will not endanger life or property, let it
  burn.
• Efforts should be directed at protecting
  surrounding property and awaiting arrival of the
  power company.

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Case Study Part II Transformer Explosion Close
Call (Please see PDF Handout)
Electrical Hazards
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Transformer Explosion Close Call
Electrical Hazards
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Transformer Explosion Close Call
Electrical Hazards
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Electrical Hazards
Transformer Explosion Close Call
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Electrical Hazards
Transformer Explosion Close Call
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Electrical Hazards
Transformer Explosion Close Call
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Discussion

• Fire and Rescue Department (FRD) personnel are
  reminded to handle transformer events similar to
  hazardous material emergencies. Prior to
  arrival, identify the hazard, deny entry, cordon
  off the area, and request the utility company. 
• All FRD personnel are reminded to increase the
  safety awareness and to provide a risk analysis
  when responding to a transformer fire. The
  decision-making process must start prior to the
  arrival and a plan to mitigate the incident
  should be discussed. This includes the level of
  PPE for the identified hazard.
• Personnel should disembark the unit in structural
  personal protective equipment (PPE) including
  SCBA. 
• A firefighter was injured when the explosion
  occurred. The firefighter received a blast
  injury to the ear, was medically assessed at the
  scene, and transported to the hospital and
  treated and released to full duty. 

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Discussion
Safety Review

• Handle switch box and transformer fires as HAZMAT
  calls.
• If you have to approach, use full PPE w/ SCBA.
• Position well away from the transformer.
• Deny entry and cordon off the area.
• Contact power company early in the incident. 
• If the transformer is on fire, do not apply water
  or other extinguishing agents, and do not
  approach it until it is confirmed de-energized.

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Discussion
Safety Review

• Look/listen for scorching, leaking fluid,
  venting, smoke, and noises.
• When in doubt, secure the area, establish a
  safety zone, allow the power company to arrive
  and determine the safe and proper course of
  action.
• Efforts should be directed at protecting
  surrounding property, while awaiting the power
  company.
• Departments need to establish training programs
  and involve the local power company.