• This forum is the machine-generated translation of www.cad3d.it/forum1 - the Italian design community. Several terms are not translated correctly.

electric car hazard

  • Thread starter Thread starter cacciatorino
  • Start date Start date
it is not a matter of being or not mouthpieces: the danger of gas or walking on a cornice see it all, regardless of the specific technical preparation due to their profession. the danger of electricity, especially in particular conditions such as these is completely unclear.

if we add that some kind of journalism echoes us above (for ignorance or sensationalism) then ideas get even more complicated. I am more than certain Roman fulvio want to discredit the author of the writing, not you hunter that the article you linked him. in this I agree: It seems to me that we both have knowledge of electrotechnics that allow us to judge the question professionally.

My comments (and I think so are those of Roman fulvio) are directed to approach the view of the public of the "unemployed" to reality, rather than the easily incendiary suggestion on the question of unfamiliar dangers.

I think it's all here, a simple misunderstanding.
 
exxon said:
here is an article that seems less sensationalistic and a little more technical.
risk of electric vehicles
Click to expand...
A little more technical, yes.
But, for example, to say that the electrolytes of motor vehicles are solid, it seems wrong. There are, but for now at the laboratory stage or small expensive productions ( yi whose stanford ) . maybe the author meant electrodes?
 
cacciatorino said:
....
Back to the subject, the reading impressed me because in my spare time I volunteer rescuer in one of the many "crosses" that are in Italy, so I could really deal with the incidental electric car.
....
Click to expand...
legitimate doubt.
in the case of an accident, the hv terminals of the battery are in contact with the rescuers and the warning that the conditions for which the battery circuit is closed are probably more rare than those in which the circuit is closed.
" beyond all procedures, consider high voltage cables active."
between the other , reading the report of the nhtsa below , I had confirmation that, in addition to the protections (as the possibility of interrupting the circuit by cutting the hv cables in appropriate points) of which it has spoken up until now, there is also a procedure (see page 7, fig.5) automatic that, in case of accident, activates the airbags and separates the contacts physically (
So if the airbags were activated, it is logical to think that even the inertial switches of the modules were activated.
Therefore, according to logic, we should be able to touch a wound in an electric car without being lightning .
But it is known that accidents are not scheduled at the table. something could always go differently.
Therefore even if the htnsa recognizes (page 10/11) that, according to its evaluations and according to the indications of some builders, there is no need to resort to individual protections for the electric risk, other builders require it (possibly to avoid any risk and download every responsibility' "some rescue data sheets (e.g. from nissan or from citroen) Dectate high-voltage gloves. ") and we'll have to "mount the situation."

My suggestion is to buy you that pair of insulating gloves from 40 € . as the formula mechanics do and .

I would also like to point out that if, in the lateral clash (because if in the front or rear shock, given the amount of metal present, something has reached the battery, I do not dare to think what will happen to the occupants ) the impact force has deformed the ring with its a and b pillars (made now for a few years in steels with uts greater than 800 or 1000 mpa as seen in the image here https://charlesdeseg.files.wordpress.com/2015/03/safe5.jpg ) difficult for you to access the wounded without any firefighters using some hydraulic device to cut the "lamiera". and even with some difficulty it seems.
 

Attachments

to prevent me from being stabbed for writing untruthful things and not editing:
1) the above research is not of nhtsa, but is of a German/Swedish consortium (eversafe).
the link with the NHTSA is due to the fact that the research was presented to one of the annual events that the latter organizes (e.g.
2) eversafe (as by name ....) is not true that it does not recommend wearing dielectric gloves, but does it "...in case of serious damage to the battery...".
 
ti
Lettore espatriato said:
legitimate doubt.
in the case of an accident, the hv terminals of the battery are in contact with the rescuers and the warning that the conditions for which the battery circuit is closed are probably more rare than those in which the circuit is closed.
" beyond all procedures, consider high voltage cables active."
between the other , reading the report of the nhtsa below , I had confirmation that, in addition to the protections (as the possibility of interrupting the circuit by cutting the hv cables in appropriate points) of which it has spoken up until now, there is also a procedure (see page 7, fig.5) automatic that, in case of accident, activates the airbags and separates the contacts physically (
So if the airbags were activated, it is logical to think that even the inertial switches of the modules were activated.
Therefore, according to logic, we should be able to touch a wound in an electric car without being lightning .
But it is known that accidents are not scheduled at the table. something could always go differently.
Therefore even if the htnsa recognizes (page 10/11) that, according to its evaluations and according to the indications of some builders, there is no need to resort to individual protections for the electric risk, other builders require it (possibly to avoid any risk and download every responsibility' "some rescue data sheets (e.g. from nissan or from citroen) Dectate high-voltage gloves. ") and we'll have to "mount the situation."

My suggestion is to buy you that pair of insulating gloves from 40 € . as the formula mechanics do and .

I would also like to point out that if, in the lateral clash (because if in the front or rear shock, given the amount of metal present, something has reached the battery, I do not dare to think what will happen to the occupants ) the impact force has deformed the ring with its a and b pillars (made now for a few years in steels with uts greater than 800 or 1000 mpa as seen in the image here https://charlesdeseg.files.wordpress.com/2015/03/safe5.jpg ) difficult for you to access the wounded without any firefighters using some hydraulic device to cut the "lamiera". and even with some difficulty it seems.
Click to expand...
Thank you for your contribution. I read the linked document and seems to calm down, even if it immediately puts its hands on the reliability of the results, for the very little case analysed.

about having to intervene on the occupants of an incidental car consider that you could have arrived on the spot before the arrival of the firefighters, and then begin to work on the injured to put the collar on it and administer oxygen, all perhaps under a flying storm, all maybe on a ten-year-old electric car and in precarious maintenance.

I think of sources of perplexity, if not of real danger, there are several.
 
exxon said:
There are procedures and protocols that rescuers know very well. Many of the risks are unknown to the most, but the operators are trained to minimize their impact on general safety (just for example, the hook that descends from a helicopter should not be grasped at the flight from a man to the ground, because the helicopter can be electrostatically charged at such a level as to move it. . . ).
Click to expand...
Therefore, in the case of the helicopter there is a risk even if at an open circuit, so why in the electric car not? Just for delta-v? What if it's raining on the spot?
 
exxon said:
My comments (and I think so are those of Roman fulvio) are directed to approach the view of the public of the "unemployed" to reality, rather than the easily incendiary suggestion on the question of unfamiliar dangers.

I think it's all here, a simple misunderstanding.
Click to expand...
you have been very kind and extremely patient, the limits are certainly mine that are lacking competence in the specific sector:):)
 
cacciatorino said:
Therefore, in the case of the helicopter there is a risk even if at an open circuit, so why in the electric car not? Just for delta-v? What if it's raining on the spot?
Click to expand...
beautiful question!

the pleasant side of discussing with "cultivated" interlocutors is that questions are intelligent and challenging. . .

in the case of electrostatic discharge (e.g. from the helicopter to the ground), it may seem that the circuit is open, but it is not so. to realize it is enough to ask "where is the generator"? and still "what are his poles"?

the generator is "distributed", consisting of the helicopter, the earth and the space interposed. these three elements form the capacitor that has loaded. The poles are the land and the helicopter. if through the cable of the winch closes the circuit from the helicopter to the earth, through the body of the person, it is lightning.

Why doesn't the same thing happen in the car case? because in this case the generator is the battery that does not have one of the poles constituted by the earth, but the poles are both of the metallic connections well defined and isolated (unless damaged) from any other accessible part.
 
exxon said:
beautiful question!

the pleasant side of discussing with "cultivated" interlocutors is that questions are intelligent and challenging. . .

in the case of electrostatic discharge (e.g. from the helicopter to the ground), it may seem that the circuit is open, but it is not so. to realize it is enough to ask "where is the generator"? and still "what are his poles"?

the generator is "distributed", consisting of the helicopter, the earth and the space interposed. these three elements form the capacitor that has loaded. The poles are the land and the helicopter. if through the cable of the winch closes the circuit from the helicopter to the earth, through the body of the person, it is lightning.

Why doesn't the same thing happen in the car case? because in this case the generator is the battery that does not have one of the poles constituted by the earth, but the poles are both of the metallic connections well defined and isolated (unless damaged) from any other accessible part.
Click to expand...
So let us see:
I have a battery full of crushed electrons who are eager to escape out to less stressful situations (at lower potential). Are you telling me that these electrons can only come out if they fall as many from the back door (the negative)?
 
the fact is that in a battery charge there are no more electrons than in a discharge. a generator of any kind is a "electron pump", not a reservoir: If you don't stick electrons on one side, you can't have them on the other!
 
exxon said:
the fact is that in a battery charge there are no more electrons than in a discharge. a generator of any kind is a "electron pump", not a reservoir: If you don't stick electrons on one side, you can't have them on the other!
Click to expand...
Yes, my question was to know if this amount of electrons present is already enough to create danger even in case of open circuit or not.
By doing the usual hydraulic analogy, it would be like putting itself under a tank of the aqueduct and opening the exhaust pipe, and hoping to resist until the tank is empty.
 
to have a difference of potential, you have to have two different potentials, if you have only one potential, you have no difference. what potential has a pole of a battery? Whatever, until you compare it to something. What pressure difference does a lake have? no, until you compare two basins to different quotas, even when it comes to pressure, we actually talk about pressure differences.
I try to give you a silly example: If you have a container full of air at 100 atm, and open it what happens? depends on the external pressure, if there is no difference, nothing happens at all.
in your room there is air at a bar about pressure, but if you open the window does not run away, unless you are in the space where the pressure is practically absolute zero, in that case you would have a lot of potential energy that is free opening the porthole of your shuttle.
 
bip said:
to have a difference of potential, you have to have two different potentials, if you have only one potential, you have no difference. what potential has a pole of a battery? Whatever, until you compare it to something.
Click to expand...
Yes, we return to the question with which I opened the discussion: with a part of the body touch an discovered terminal connected the positive and with another part of the body are on the ground: I would say that my body sees a delta-v even in the case of open circuit, delta that will go away exhausting as the electrons flow from positive to earth, but that at least initially could be sensitive.
 
electric/hydraulic analogies are subdoles and often fail to effectively illustrate the reality of the facts.

First of all it must be remembered that an unconnected electric wire represents a tube with closed ends, not an open tube capable of pouring liquid on the outside.

That is then that a pump, however powerful it is, if it has the closed aspiration, cannot move anything at the exit.

for how much water (electrons) there is inside the pump, the same does not move if the input is obstructed (free pole) and no current (flux of liquid) can flow.
 
cacciatorino said:
Yes, we return to the question with which I opened the discussion: with a part of the body touch an discovered terminal connected the positive and with another part of the body are on the ground: I would say that my body sees a delta-v even in the case of open circuit, delta that will go away exhausting as the electrons flow from positive to earth, but that at least initially could be sensitive.
Click to expand...
I answer with a question: How much is the potential difference between the ground and the positive pole of the battery? if the negative pole is isolated from the ground, the difference of potential is zero, the circuit is open.
is the same two-page speech by now
 
in use and uk government agencies invite rescue services to incidental electric cars to intervene with greater caution not only for fear of possible fires but for possible damage from electric shocks, so that in use periodic meetings between the construction houses and the so-called road rescue, will be excess of prudencehttp://www.hse.gov.uk/mvr/topics/electric-hybrid.htmhttps://www.nfpa.org/training-and-e...fety-training/emergency-response-guides/teslahttps://www.nfpa.org/training-and-events/by-topic/alternative-fuel-vehicle-safety-training
 
bip said:
I answer with a question: How much is the potential difference between the ground and the positive pole of the battery? if the negative pole is isolated from the ground, the difference of potential is zero, the circuit is open.
is the same two-page speech by now
Click to expand...
I don't know, we also talked about not having to take the rope of the helicopter winch, or we have physical evidence of arches that create between the clouds and the earth.
 

Forum statistics

Threads
44,997
Messages
339,767
Members
4
Latest member
ibt

Members online

No members online now.
Total: 0 (members: 0, guests: 0)
Back
Top