Short circuit?

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alfranken said:
I watched it but the whole exterior structure didnt go up in flames! Could dousing with gasoline the outer exterior of a small house be the only way in which it would engulf in flames???
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It is really amazing how fast entire structures can become fully involved once a fire starts. There are lots of factors that enter into it, especially the type of construction and how dry everything is.
 
don_resqcapt19 said:
It is really amazing how fast entire structures can become fully involved once a fire starts. There are lots of factors that enter into it, especially the type of construction and how dry everything is.
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Old barracks, late 60s, at Fort Lewis took 10 minutes to be fully engulfed once a fire got started. Why everyone had a stint at walking fire watch. DIs were pretty adamant.
 
hbiss said:
At this point I have to ask, what is your interest here? Did your house burn down and you suspect arson?

-Hal
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Because police usually are able to determine when arson is the cause probably most likely because gasoline was used... Then how could an arson fire be started then without using gasoline?
 
alfranken said:
But is there any possibility that an arson fire could be started without police being able to determine that it indeed was arson? Does arson always leave evidence regardless of what method was employed?
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No, arson does not always leave evidence.
 
alfranken said:
Because police usually are able to determine when arson is the cause probably most likely because gasoline was used... Then how could an arson fire be started then without using gasoline?
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Im glad you are trying to educate yourself, so-
Determination is the job of the fire dept, not police. Did you know 2 sticks feverishly rubbed together makes fire?
I suggest watching "quest for fire" for your next lesson- it covers gathering and procreation as well as fire making. And rea don chong is half neked...
 
rambojoe said:
Im glad you are trying to educate yourself, so-
Determination is the job of the fire dept, not police. Did you know 2 sticks feverishly rubbed together makes fire?
I suggest watching "quest for fire" for your next lesson- it covers gathering and procreation as well as fire making. And rea don chong is half neked...
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But how can rubbing two sticks produce fire in such a way as to engulf a pretty small house exterior surface behemently so its almost as though it had been doused with gasoline? How can the fire remain strong for fairly a while then? If the small house is like hard stucco on the outside then?
 
Pure speculation;
If a utility primary wire were to fall and make contact with the service line going into a house, the higher voltage of the primary line would be too much for any protective device in the house to interrupt, even if it did try to. The high voltage would just jump the gaps and energize every wire inside of the house. Then, every switch and receptacle and junction box in the walls would instantly become an arc point, so essentially turning the entire wiring system of the house into a huge set of incendiary devices simultaneously. In an old house with super dry framing members and wood siding would be completely engulfed in flame in a matter of minutes.

On the utility side, primary lines would have protection breakers on them, but may have had what's called a "recloser", a system by which they attempt to restart the lines over and over in case the cause was a tree limb or something that may burn away, so they can keep everyone from having a long blackout. So repeated reclosings into that crossed line would exacerbate the fire starting capability.
 
hbiss said:
Someone doing this intentionally would be very unlikely. Damaging the service in some way would likely only result in localized damage to the house because of the way the service is installed. Services are installed so to minimize the possibility of fire damage.

As was said, if the whole house was involved, the cause has to be a primary to secondary cross. That would put high voltage (7,000 to 12,000 volts) on the service going into the house which would put it on all the house wiring which would cause fires to erupt all through the house. All electrical equipment would burst into flames.

Neither of those videos above illustrate this. Those are only downed high voltage power lines.

The only place a primary to secondary cross could occur is out on the street when a high voltage conductor at the top of the poles is damaged for some reason, falls down and contacts the secondary conductors below. There is no way somebody is going to do that intentionally.

We have a video of a whole neighborhood involved but it was a long time ago and I can't find it.

-Hal
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Doesn't necessarily have to be at top of pole though that would be the most common situation.

POCO in this area made a repair to an underground 34.5 kV line a few years ago. When they energized it the repair failed. It somehow arced over to nearby barbed wire fence, which had telephone pedestal enclosures in close proximity and of course got into the shield of the phone cables and there were many damages within couple miles radius of the repair location via the phone cables.
 
Jraef said:
Pure speculation;
If a utility primary wire were to fall and make contact with the service line going into a house, the higher voltage of the primary line would be too much for any protective device in the house to interrupt, even if it did try to. The high voltage would just jump the gaps and energize every wire inside of the house. Then, every switch and receptacle and junction box in the walls would instantly become an arc point, so essentially turning the entire wiring system of the house into a huge set of incendiary devices simultaneously. In an old house with super dry framing members and wood siding would be completely engulfed in flame in a matter of minutes.

On the utility side, primary lines would have protection breakers on them, but may have had what's called a "recloser", a system by which they attempt to restart the lines over and over in case the cause was a tree limb or something that may burn away, so they can keep everyone from having a long blackout. So repeated reclosings into that crossed line would exacerbate the fire starting capability.
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This is how it can engulf the house in minutes then add as mentioned earlier that the amount of heat in the arcing can be pretty high, probably higher than a gasoline accelerated fire would burn. You could easily have conductors in many more places that are contributing to the spread of the fire than you would have with someone spreading a few gallons of gasoline through the house to intentionally burn it down. Gasoline doesn't burn, or at least doesn't burn well, it's vapors however do. Pouring gasoline on the floor then lighting it can burn the whole house down, but depending on conditions may take some time to fully engulf the place. When that gas is burning it is mostly burning vapors from a point a little above the surface so a surface that doesn't absorb the gas could be possible to burn off all the gas and fire goes out with somewhat minimal damage.
 
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