Electrical Hazards for Fire and Rescue Departments Part I: Fire Department Vehicles Contacting Wires Captain I Gary C. Dize Health and Safety Division Fairfax County, Virginia

Electrical Hazards Common Types of Electrical Hazards Fire Department Vehicles Contacting Wires Transformer Fires – Ground and Substation Fires Near High Tension Power Lines 2

Electrical Hazards Operating Near Wires Treat all wires as dangerous and energized at high voltage until tested and proven otherwise. Typically there are three primary lines (top lines) which carry 19,900 volts each and two neutral lines 9.5 feet below the primary lines. Beneath these lines are cables belonging to other utilities. The voltage decreases as the distance from the point of contact increases. This is known as the Step Potential.

Electrical Hazards The action of placing the aerial ladder near the electrical lines endangers the life and safety of anyone who was operating near the vehicle. Manufacturer recommendations and OSHA standards indicate that the ladder should not be positioned within 10 feet of power lines. This precaution is clearly indicated numerous times on the exterior of all of the department aerial devices as well as on the control pedestal.

Electrical Hazards Exercise extreme caution when approaching the scene, especially when visibility is low due to smoke or operating during the night. Know your first due and pre-plan for over head wires. Establish a safety zone and prevent all unauthorized persons from approaching the scene. Brief arriving unit officers of any electrical hazards including overhead wires.

When a vehicle comes into contact with power lines: Electrical Hazards When a vehicle comes into contact with power lines: Establish a safety zone. The ground around the vehicle may be energized. Unless threatened by fire or some other danger, occupants should remain on the vehicle until the power is confirmed off. The entire vehicle may be energized, causing tires and fluids to burn, and other components to fail, especially pressured cylinders and hydraulic tools.

Electrical Hazards Case Study: Part I Close call involving ladder running into power line (Please see PDF Handout)

Discussion The action of placing the aerial ladder near the electrical lines endangered the life and safety of anyone who was operating near the vehicle.   The manufacturer recommendations and OSHA standards indicate that the ladder should not have been positioned within 10 feet of power lines. This precaution is clearly indicated numerous times on the exterior of all of the department’s aerial devices as well as on the control pedestal. Members should avoid touching apparatus while aerial is in use.

Discussion Does your Department have a process for training drivers and backup drivers ?  Is the process for qualifying personnel to drive and operate vehicles taking place at the station/shift level? This would results in a variety of training procedures and a range of criteria to become a driver.  

Discussion Does your department’s apparatus qualifications checklists make the distinction between the various types of vehicles in the department’s fleet? Does the “aerial” checklist makes the distinction between rear-mount aerials, rear-mount towers, and mid-mount towers, and does it account for vehicles from different manufacturers? An In-Station Drill should be developed and issued to provide information to members on the hazards of electricity, the components of the distribution system, and guidelines for handling incidents involving electricity.

The training should cover topics such as: Discussion The training should cover topics such as:  Basic information about electricity, the components that comprise the distribution system and the hazards presented by both. Awareness of overhead hazards when deploying ground ladders, aerial devices, and other devices such as light towers, antennae, cameras, etc. Guidelines for handling “routine” events involving electricity, as well as unusual events. Considerations of routine aerial maintenance and hazard awareness.