NFPA ELECTRIC VEHICLE SAFETY FOR EMERGENCY RESPONDERS

Module VI:Course Conclusion

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Module I - Introduction

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Why is this course important to you as an emergency responder?

HEV Hybrid Electric VehicleA vehicle that has both an internal combustion engine (ICE) and electric motor(s).

PHEV Plug-In Hybrid Electric VehicleA vehicle that has both an ICE and electric motors, and can recharge its batteries from an external electric power source.

EV Electric VehicleA vehicle which uses only electric motor(s) for propulsion.

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Definitions

Dispelled Myths about P/HEVs and EVs

• They are just a fad.

• Special equipment is needed for vehicle fires.

• Extrications will be greatly hampered by high voltage wiring.

• HV batteries will leak a significant amount of electrolyte if damaged or breached.

• Electrocution is likely from touching a vehicle that is involved in a crash or submerged.

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Truths about P/HEVs and EVs• Hybrid and Electric Vehicles may move

silently on their own power at a scene.

• They can be difficult to distinguish from conventional vehicles.

• Use of P/HEVs and EVs is increasing exponentially.

• P/HEVs and EVs utilize high voltage electricity, and safety precautions must be taken by responders.

NFPA ELECTRIC VEHICLE SAFETY FOR EMERGENCY RESPONDERS

Module VI:Course Conclusion

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Module II – Basic Electrical Concepts & Hazards

Voltage•Electrical potential. Comparable to water pressure or pounds per square inch (PSI) in a hose.•Measured in Volts

Current•Quantity of electrons flowing. Comparable to gallons per minute (GPM) flow of a hose.•Measured in Amperes

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Definitions

Resistance•Material’s resistance to conducting current. Comparable to friction loss in a hose line.•Measured in Ohms

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● With both AC and DC, there must be a completed path, or circuit, for current to flow.

● A switch creates a break in the circuit when “OFF”.

● Turning the switch “ON” completes the circuit, allowing current to flow.

Understanding Electrical Circuits

OFF

ON

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Electrical Circuits in Vehicles● Both AC and DC circuits can be used.

● All HV circuits are completely isolated from the chassis.

● Unlike a structure, no circuits are grounded to earth.

● Electrocution hazard exists when a body becomes part of a completed circuit.

NFPA ELECTRIC VEHICLE SAFETY FOR EMERGENCY RESPONDERS

Module VI:Course Conclusion

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Module III – Vehicle Systems and Safety Features

Standard Components

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•12 Volt DC battery• Found in P/HEVs and EVs.• Can be found in various

locations.

• Internal combustion engine• Found in P/HEVs and

extended range electric vehicles.

Internal Combustion Engine

12 VDC Battery

Standard Components

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High Voltage Battery• Found in P/HEVs and EVs.

• NiMH or Lithium Ion.

• Multiple low voltage cells wired in series.

• Typical locations in Vehicle:

• In the cargo area or under the 2nd row seat (SUVs) in P/HEVs,

• Under the floor pan in EVs.

Standard Components

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•DC/DC Converter• Replaces conventional alternator.

• Takes high voltage DC current from battery and steps it down to 12v DC to run vehicle systems.

•Inverter/Converter• Found in vehicles

with AC motors.

• Converts DC current to AC to run motor.

Standard Components

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•Electric Cables• Standard 12v DC as in conventional vehicles.• Intermediate voltage (30v-60v) – Blue or Yellow.• High Voltage (60v +) – Orange.

•Electric motor• Found in all P/HEVs and EVs.• Not typically visible.

•Charging port• Found in all PHEVs and EVs.• Typically on a front fender

or in the grill of vehicle.

Safety Systems

● Crash Impact

● Airbag Deployment

● Cabling damage

● Short Circuits

Designed to shut down the high voltage systems in the event of:

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High voltage circuit isolation from the chassis provides additional protection.

Charging Stations

Level I120 VAC

8-16 hours

Level II240 VAC3-8 hours

DC Quick Charge480 VDC

20-30 min.

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NFPA ELECTRIC VEHICLE SAFETY FOR EMERGENCY RESPONDERS

Module VI:Course Conclusion

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Module IV – Initial Response: Identify, Immobilize &

Disable

Initial Procedures

● Scene Size Up.

● Utilize appropriate PPE for operations.

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Identify

Immobilize

Disable

Four methods:

Formal Identification

Informal Identification

Telematics

Emergency Field Guides

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Identify

Formal Identification includes badges and labels.

May be located anywhere. Most common locations are

Front fendersDoorsRear of vehicleDashboardEngine

No standardization

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Identify

Informal Identification includes distinctive HEV/PHEV/EV components and warnings

READY

Battery ventsInstrument panel itemsWarning labelsHigh voltage cables

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Identify

NFPA EmergencyField Guide

Telematics: electronic systems which transmit information from vehicle to responders.

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Identify

Immobilize

● Chock the wheels.● Place vehicle in park.● Engage the emergency brake.

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Disable

● Shut Off Vehicle Ignition● Disconnect 12 VDC Battery

Primary Method

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Disable

● Disconnect 12 VDC Battery.● Pull the high voltage system control fuse.

Secondary Method (For some models)

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High Voltage System Drain-Down● Some models have capacitors that can retain HV energy for up to 10 minutes.

● After system is shut down, the high voltage battery still

retains its charge.

● Always assume the system is still energized.

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High Voltage Batteries

Service Disconnects

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● Recommendations for use and required safety equipment vary by manufacturer. Consult appropriate ERG before using service disconnect. ● Located on the battery.

● Cuts off the battery from the high voltage system.

NFPA ELECTRIC VEHICLE SAFETY FOR EMERGENCY RESPONDERS

Module VI:Course Conclusion

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Module V – Emergency Operations

Extrication

● High voltage components and cabling are usually not in typical “cut points.”

● Before conducting extrication operations, determine location of:

● Occupant Protection Systems

● High Voltage Components

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Battery Breach

● Unlikely due to location and protective cases.

● Batteries are dry cell. Only a small amount of electrolyte would leak if crushed.

● Some models will leak liquid coolant.

● There is high voltage electrical shock hazard if a battery is breached.

● Follow local medical protocols in the event of exposure to electrolyte.

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Submersion

● HV system is isolated from the chassis.

● Electrical systems designed to NOT energize water.

● Damaged high voltage components could present a contact hazard.

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Vehicle Fires

● Use NFPA compliant firefighting PPE and respiratory protection. ● Utilize standard equipment for extinguishing any vehicle fire.

● Electrical system design doesn’t support current flow through hose stream.

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Vehicle Fires

● Do NOT use equipment to pierce hood, due to HV components and cabling near surface.

● Follow normal emergency shutdown procedures.

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Incidents Involving Charging Stations

Fires● Treat as a standard

energized electrical fire.

● Shut down power to charging station.

● Perform extinguishment operations.

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National Fire Protection Association

End of Course

Electric Vehicle Safety for Emergency Responders

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