[Amps] AC wiring

[m.ford]

----- Original Message ----- 
From: "Gary Schafer" <garyschafer at comcast.net>
To: "'m.ford'" <k1ern at direcway.com>; "'R.Measures'" <r at somis.org>
Cc: <amps at contesting.com>
Sent: Thursday, October 20, 2005 8:10 PM
Subject: RE: [Amps] AC wiring


> 
> 
>> -----Original Message-----
>> From: amps-bounces at contesting.com [mailto:amps-bounces at contesting.com] On
>> Behalf Of m.ford
>> Sent: Thursday, October 20, 2005 11:16 AM
>> To: R.Measures
>> Cc: amps at contesting.com
>> Subject: Re: [Amps] AC wiring
>> 
>> 
>> ----- Original Message -----
>> From: "R.Measures" <r at somis.org>
>> To: "Tony King - W4ZT" <amps080605 at w4zt.com>
>> Cc: <amps at contesting.com>
>> Sent: Thursday, October 20, 2005 8:30 AM
>> Subject: Re: [Amps] AC wiring
>> 
>> 
>> >
>> > On Oct 19, 2005, at 1:13 PM, Tony King - W4ZT wrote:
>> >
>> >> Seems a lot of folks have opinions and that is a good thing. Perhaps I
>> >> am just a little more anal about keeping wires cool (yes, I HAVE had a
>> >> house fire). Fortunately it wasn't caused by under sized electrical
>> >> service.
>> >>
>> > The last house fire in this neighborhood was caused by rodents eating
>> > the vinyl insulation on electrical wires.  This happened after the new
>> > owner of the house decided to get rid of all the cats living on his 2.5
>> > acres.
>> >
>> I lost everything in a house fire in 1978. Caused by red squirrels chewing
>> on the newly installed Romex. The arc in the wall was extinguished when
>> the newly installed circuit breaker welded shut causing the pole pig to
>> boil.
>> Had they left the original plug fuses and panel in place the old farmhouse
>> would still be here. The NEC can spec all the interupting capacity they
>> want
>> but plug fuses don't know jack about  di/dt  and everytime I see another
>> house
>> fire I gotta wonder.
>> 
>> Mike k1ern
> 
> 
> This doesn't add up. Are you telling us that both your breaker on the romex
> line and your main panel breaker welded shut?

Negative. The 20 amp 120 volt romex line breaker welded shut.
The 100 amp main breaker never opened and the 10 kva transformer
happily provided everything it could until it opened. It was to late.
The inside of the wall was on fire. It was dark. Time to go.

It is my understanding that an arc will only self extinguish if
    a. The path is made longer (wires seperate)
    b. A bigger arc is drawn elswhere (breaker opening)
    c. The source is removed (roasted pole pig)

I'll bet that failure mode has been the root cause of a lot of fires.
Any insurance types care to comment?

Mike k1ern



> 
> I do agree that fuses are more reliable than breakers. Some breakers are
> very far off from what they are stated to trip at.
> 
> 73
> Gary  K4FMX
> 
> 
> 
> 
> --