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NFPA ELECTRIC VEHICLE SAFETY FOR EMERGENCY RESPONDERS
Module VI:
Course Conclusion
Module I - Introduction
6-1
Why is this course important to
you as an emergency responder?
6-2
Definitions
HEV Hybrid Electric Vehicle
A vehicle that has both an internal combustion
engine (ICE) and electric motor(s).
PHEV
Plug-In Hybrid Electric Vehicle
A vehicle that has both an ICE and electric
motors, and can recharge its batteries from an
external electric power source.
EV
Electric Vehicle
A vehicle which uses only electric motor(s)
for propulsion.
6-3
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.
6-4
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.
6-5
NFPA ELECTRIC VEHICLE SAFETY FOR EMERGENCY RESPONDERS
Module VI:
Course Conclusion
Module II – Basic Electrical
Concepts & Hazards
6-6
Definitions
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
Resistance
•Material’s resistance to conducting current.
Comparable to friction loss in a hose line.
•Measured in Ohms
6-7
Understanding Electrical
Circuits
● With both AC and DC, there must
be a completed path, or circuit, for
current to flow.
ON
OFF
● A switch creates a break in the
circuit when “OFF”.
● Turning the switch “ON” completes
the circuit, allowing current to flow.
6-8
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.
6-9
NFPA ELECTRIC VEHICLE SAFETY FOR EMERGENCY RESPONDERS
Module VI:
Course Conclusion
Module III – Vehicle Systems
and Safety Features
6-10
Standard Components
•12 Volt DC battery
•Found in P/HEVs and EVs.
•Can be found in various
locations.
12 VDC Battery
• Internal combustion engine
•Found in P/HEVs and
extended range electric
vehicles.
Internal Combustion
Engine
6-11
Standard Components
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.
6-12
Standard Components
•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.
6-13
Standard Components
•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.
6-14
Safety Systems
Designed to shut down the high
voltage systems in the event of:
● Crash Impact
● Airbag Deployment
● Cabling damage
● Short Circuits
High voltage circuit isolation from the chassis
provides additional protection.
6-15
Charging Stations
Level I
Level II
120 VAC
8-16 hours
240 VAC
3-8 hours
DC Quick
Charge
480 VDC
20-30 min.
3-16
NFPA ELECTRIC VEHICLE SAFETY FOR EMERGENCY RESPONDERS
Module VI:
Course Conclusion
Module IV – Initial Response:
Identify, Immobilize & Disable
6-17
Initial
Procedures
●
Identify
Scene Size Up.
Immobilize
●
Utilize
appropriate PPE
for operations.
Disable
6-18
Identify
Four methods:
Formal Identification
Informal Identification
Telematics
Emergency Field Guides
6-19
Identify
Formal Identification includes
badges and labels.
May be located anywhere.
Most common locations are
Front fenders
Doors
Rear of vehicle
Dashboard
Engine
No standardization
6-20
Identify
Informal Identification includes distinctive
HEV/PHEV/EV components and warnings
READY
Battery vents
Instrument panel items
Warning labels
High voltage cables
6-21
Identify
Telematics: electronic systems
which transmit information
from vehicle to responders.
NFPA
Emergency
Field Guide
6-22
Immobilize
● Chock the wheels.
● Place vehicle in park.
● Engage the emergency brake.
6-23
Disable
Primary Method
● Shut Off Vehicle Ignition
● Disconnect 12 VDC Battery
6-24
Disable
Secondary Method
(For some models)
● Disconnect 12 VDC Battery.
● Pull the high voltage system control
fuse.
6-25
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.
6-26
High Voltage Batteries
Service Disconnects
● 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.
6-27
NFPA ELECTRIC VEHICLE SAFETY FOR EMERGENCY RESPONDERS
Module VI:
Course Conclusion
Module V – Emergency
Operations
6-28
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
6-29
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.
6-30
Submersion
● HV system is isolated from the chassis.
● Electrical systems designed to NOT
energize water.
● Damaged high
voltage
components
could present a
contact hazard.
6-31
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.
6-32
Vehicle Fires
● Do NOT use equipment
to pierce hood, due to
HV components and
cabling near surface.
● Follow normal
emergency shutdown
procedures.
6-33
Incidents Involving Charging Stations
Fires
● Treat as a standard
energized electrical
fire.
● Shut down power
to charging
station.
● Perform
extinguishment
operations.
6-34
National Fire Protection Association
End of
Course
Electric Vehicle Safety for
Emergency Responders
Copyright ©2011 National Fire Protection Association. Single copies may be
made for specific non-profit educational uses with permission.
No commercial or mass distribution allowed.
6-35