Because the plastic holder melts/burns/disappears in a fire, leaving a
hole for fumes (and possibly creating fumes), flames and a short from
the "bolt" to the firewall.
Dick Tasker
John Grosse wrote:
> <grosseair@comcast.net>
>
> I'm sorry, but I'm not understanding something. The devices below look
> more secure to me than a wire through a hole in the firewall filled
> with fire putty. I can see that the bolt could conduct heat from a
> fire, but then so could a wire. The concept with these devices seems
> the same to me as a bulkhead fitting for hydraulic lines which is
> apparently okay. So could someone explain why these electrical
> fittings are incompatible with firewall security.
>
> Thanks.
>
> John Grosse
>
> Robert L. Nuckolls, III wrote:
>> At 08:37 AM 3/10/2010, you wrote:
>>>
>>> David,
>>>
>>> I can tell you there is more than one way to skin a cat, but if you
>>> look
>>> at one of the gazillion Piper Cherokees out there, the cable runs from
>>> under the back seat along the left panel through the generally dry
>>> rotted grand-daddy grommet to the contactor mounted on the firewall.
>>> Size does matter but for 2 or 4 GA that won't make a difference. Good
>>> enough for Piper...
>>
>> I don't think I've yet seen a commercial-off-the-shelf firewall
>> feedthru where the insulating material would have stood off
>> Jack Thermin's "puff the magic dragon" test. Electrically
>> and mechanically, these critters function as advertised.
>> The price is low and they seem adequately robust.
>>
>> However, if one subscribes to the notion of protecting
>> firewall integrity with processes like . . .
>>
>> http://www.aeroelectric.com/articles/Firewall_Penetration/firewall.html
>>
>> then devices like . . .
>>
>> Emacs!
>>
>>
>> and . . .
>>
>> Emacs!
>> Are incompatible with the design goal cited in the
>> article. So if your design goals include attention
>> to details of fire-wall integrity, then perhaps
>> single fat-wires are best brought through grommets
>> with fire-shields and application of fire-putty
>> per Tony B's writings.
>>
>> Bob . . .
>
>
