Posted on 05/04/2004 12:03:08 PM PDT by The South Texan
By PATRICK WALTERS
ASSOCIATED PRESS
PHILADELPHIA (AP) -
The growing popularity of hybrid vehicles is a step toward cleaner air and less dependence on gasoline. But for rescuers at accident scenes, they represent a potential new danger: a network of high-voltage circuitry that may require some precise cutting to save a trapped victim.
"You don't want to go crushing anything with hydraulic tools," said Samuel Caroluzzi, an assistant chief with the Norristown Fire Department outside Philadelphia. "It's enough to kill you from what they're telling us in training."
Hybrids draw power from two sources, typically a gas or diesel engine combined with an electric motor. The battery powering the electric motor carries as much as 500 volts, more than 40 times the strength of a standard battery.
That worries those who must cut into cars to rescue people inside.
"If you can't shut it down, you don't know where the high voltage is," said David Dalrymple, an emergency medical technician in New Brunswick, N.J.
Manufacturers have put in place a laundry list of safety checks that the car's computer must go through for the electrical system to run. They've published guides showing where the electric components are on their models; on the Toyota Prius and other hybrids, the high-power cables are colored bright orange to catch the eye of a rescue worker or a mechanic.
But there are concerns over what happens if something goes wrong and the battery, ignition and other points are inaccessible.
"It's the 'what-if' that worries me," said David Castiaux, an instructor for Mid-Del Technology Center in Del City, Okla., who teaches rescue workers about hybrids.
Chris Peterson, a service training instructor for Toyota, said the Prius' electric system should shut down if anything goes wrong. "There should not be high voltage in those cables, but I'm not going to stand up and say there isn't," he said.
First responders are taught to disconnect the battery and turn off the key immediately before cutting into a car, but that's not always possible.
"Years ago you could just cut with your extrication tools through a post, but now you have to look before you cut," said Ken Nelsen, chief of the Iselin Fire Department District 11 in Woodbridge Township, N.J. "It's just another thing you need to worry about."
When air bags started becoming more common in the 1980s, rescue workers became aware of their potential to seriously injure or kill when inflated. Those concerns have been heightened now that the safety devices are being installed in side panels, seats and other areas.
Concerns about hybrids are increasing in large part because of their growing popularity. Sales have risen at an average annual rate of 88.6 percent since 2000 and recent figures show the number of Americans driving them jumped more than 25 percent from 2002 to 2003.
The Honda Insight and the Toyota Prius are common now and more are on the way: hybrid versions of the Ford Escape, Honda Accord and Lexus SUV this year, and a Toyota Highlander in 2005.
The Alachua County Fire Rescue in Gainesville, Fla., even has two hybrids of its own. Although its crews haven't had to deal with a hybrid crash, they've been getting versed on what to do when it happens, said Cliff Chapman, assistant chief.
They know not to cut into a hybrid's doors - that's where many of the cables are - and to peel off the roof instead. They also now operate under the assumption that a car is energized, wearing rubber gloves and boots.
Manufacturers say they will continue to keep rescue personnel up to date on their hybrids. But they also contend that hybrids can be seen as safer than regular cars.
"Everybody's concerned about the electrical side, but could you imagine if we tried to bring gasoline out today as a motor fuel?" Peterson said.
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On the Net:
Mid-Del Technology's training center: http://www.evtraining.com/
Honda Insight: http://www.insightcentral.net/
Toyota Prius: http://www.toyota.com/prius/
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It's current that kills you, not voltage.
Run for the hills! The difference is that these aren't going to leak acid out all over the road. I wonder how they do with heat? Wouldn't want to put anything possibly explosive in a car, like batteries or something else like highly cumbustible liquids.
. . . radio amateur and wife of Ga Tech '73 graduate . . .
A bit of specialized training for the EMS people will educate them as to where the disconnect is and what not to touch if it is still hot.
Yah. I ended up one day completing the circuit on a 450VDC plate (as in "vacuum tube") supply. But it was my lab partner who fell off his stool...
However, voltage is a measure of potential. Ohm's Law dictates that the higher the voltage the higher the current (Amps) fgiven the same resistance, provided the battery has sufficient capacity to make the current. If you take ordinary car batteries and string about 25 of them together in series, the result will kill you. In other words highe voltage trnslates into higher current.
Any battery capable of an output sufficient to drive an automobile will have the storage capacity to provide the current.
The author's wording could have been more articulate, but the concept is correct.
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