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#132898 - 09/05/01 11:38 AM Fires & Electrocutions  
pauluk  Offline
Member
Joined: Aug 2001
Posts: 7,520
Norfolk, England
Going off on a tangent slightly from the overcurrent protection topic:

I have a book here published nearly 25 years ago which indicates that electrocutions at that time were averaging about 100 per year across the country (population approx. 55 million). I'm not sure what the current statistics are on this; I'll see if I can find out.

(By the way, the 100 figure doesn't include executions: We never used the chair here.)

I do know, however, that in the last few years there has been a significant rise in the number of house fires attributed to electrical wiring.

Apparently many of the fires are in NEWER houses, or those which have been refurbished in more recent times, which somewhat goes against the natural tendency to blame old wiring.

I have a possible theory {Enter soapbox mode....]

Most people here naturally believe that as time goes on the regulations become more stringent. However, the current IEE Regs. actually allow cables to run at higher currents and temperatures than in the past.

If grouping and ambient temperature derating factors are applied, then the figure come out more equal, but the basic rating for a single cable, open to air is higher now than ever before.

It's also in the last 15 to 20 years or so that energy efficiency and extra insulation has become a big thing here. The guy stuffing fiberglass around everything he can find in the attic doesn't know - much less care - about derating factors and just covers up everything in sight.

Couple all that with the sometimes attrocious DIY extensions and incorrect fusing, and I wouldn't mind betting that THAT is the reason for the big increase in fires. Just my opinion, of course.

OK, [Exit soapboax].


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#132899 - 09/05/01 03:29 PM Re: Fires & Electrocutions  
mickky  Offline
Member
Joined: Jul 2001
Posts: 43
toronto
The various postings concerning things like 1850w hair dryers are instances supporting your observations, Paul.


#132900 - 09/05/01 05:53 PM Re: Fires & Electrocutions  
Bill Addiss  Offline
Member
Joined: Oct 2000
Posts: 3,878
NY, USA
Paul,

Besides the items that you mentioned, I think that many consumers are finding an increasing "comfort" with Electricity that might allow them to try 'fooling around with Electric' This is also fueled by the plethora of DIY resources that have been pushed upon the public recently promising them that they really can do it themselves. It's too bad that the dangers don't get equal time. But I guess that wouldn't help them sell their products.

Bill


#132901 - 09/05/01 06:38 PM Re: Fires & Electrocutions  
sparky  Offline
Member
Joined: Oct 2000
Posts: 5,311
There are many factors that sum up to an electrical mishap which are not always evident having only a cellarhole to view.
[Linked Image]


#132902 - 09/05/01 06:57 PM Re: Fires & Electrocutions  
pauluk  Offline
Member
Joined: Aug 2001
Posts: 7,520
Norfolk, England
Quote
Originally posted by Bill Addiss:
This is also fueled by the plethora of DIY resources that have been pushed upon the public recently promising them that they really can do it themselves.


I think you make a very valid point here. Our TV screens are full of such DIY shows these days.

A short while ago I happened to see a DIY electrical video tape in my local library. It offered "easy to view & understand" step-by-step guidance for such things as adding an extra socket, fitting wall lights, etc., so out of curiosity I borrowed it to watch.

One or two items were fairly easy to follow, but a lot of the "easy step-by-step guidance" was just going to lead people into big trouble as far as I could see.

One section sticks in my mind: How to add a switch to convert a ceiling light to 2-way (3-way) switching & add wall lights at the same time.

First time through I was completely confused, so I hit rewind & watched again. And again. In the end, I had to sit down with pencil & paper, and sketch out what was going on, using pause and review regularly. Even then I had to watch it slowly about five times to figure out what they were doing.

Now if it took me that long, however is the average DIYer going to understand it? The section in question also made the assumption that the existing wiring was done in one certain way, with no mention of the fact that a house may be wired differently.

Believe it or not, the final section launched into an attempted explanation of service bonding.

I felt that the whole approach was so poorly conceived, that when I returned the tape, I actually voiced my concerns to the head librarian & suggested that the tape be withdrawn before somebody got hurt.


#132903 - 09/05/01 08:03 PM Re: Fires & Electrocutions  
sparky  Offline
Member
Joined: Oct 2000
Posts: 5,311
........add to it all the DYI books, and TV shows. i complain about all the DYI boo-boo's i have to fix , the irony being the more the cocept is pushed the busier i am
[Linked Image]


#132904 - 09/05/01 08:16 PM Re: Fires & Electrocutions  
sparky  Offline
Member
Joined: Oct 2000
Posts: 5,311
(By the way, the 100 figure doesn't include executions: We never used the chair here.)

hey...remember 'the Green Mile", guess it really happened!!!
[Linked Image]

1990: The first in a string of botched electrocutions in Florida spurs public outrage at the practice: Six-inch flames erupted from Jesse Tafero's head because prison officials replaced the worn-out sponge in the chair's head electrode with a synthetic household sponge, which caught fire.


#132905 - 09/06/01 06:28 PM Re: Fires & Electrocutions  
pauluk  Offline
Member
Joined: Aug 2001
Posts: 7,520
Norfolk, England
Yes,I've seen that report on a website. I understand they've had quite a lot of trouble with "Old Sparky" in Fla. recently which prompted the state legislature to follow the example of many others and introduce lethal injection.

Saw one report (Alabama, I think) where on the first try a warden said they'd got the cables to the chair wired wrong back to the control gear.

One connection to head, one to ankle: Must take a lot of practice to be able to get that wrong!


#132906 - 09/06/01 07:40 PM Re: Fires & Electrocutions  
bordew  Offline
Member
Joined: Aug 2001
Posts: 142
Vienna,Ohio, USA
Quote
Originally posted by pauluk:
Yes,I've seen that report on a website. I understand they've had quite a lot of trouble with "Old Sparky" in Fla. recently which prompted the state legislature to follow the example of many others and introduce lethal injection.

Saw one report (Alabama, I think) where on the first try a warden said they'd got the cables to the chair wired wrong back to the control gear.

One connection to head, one to ankle: Must take a lot of practice to be able to get that wrong!



Its like anything else, if you only do it once every couple years, it is tough to get it right the first time. Solution ? Practice makes perfect. My God, they use what, 24kv, how in the world can they screw that up.


#132907 - 09/06/01 08:01 PM Re: Fires & Electrocutions  
pauluk  Offline
Member
Joined: Aug 2001
Posts: 7,520
Norfolk, England
Quote
Originally posted by bordew:
Practice makes perfect. My God, they use what, 24kv, how in the world can they screw that up.


All the reports I've seen say between about 1700 and 2400 volts with a resulting current of 4 to 6A. Amazing how low the resistance of a human body can be, but as you say, it seems incredible that they sometimes need 2, 3, or even more jolts.


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