Re: Insteon Observations

[Bud-- <remove.BudNews@xxxxxxx>]

TKM wrote:

> "G. Morgan" <alarmpro@xxxxxxxxxxx> wrote in message
> news:cnt6o2p66td2u9s7k2pntcrjg8v6voadrr@xxxxxxxxxx
>
>>On Fri, 15 Dec 2006 21:24:59 -0700, AZ Woody <reply@here> wrote:
>>
>>
>>>Dave Houston wrote:
>>>
>>>>G. Morgan <alarmpro@xxxxxxxxxxx> wrote:
>>>>
>>>>
>>>>>Anyway,  I have never experienced what you describe (a circuit breaker
>>>>>trip) on failure of a bulb.  My common sense tells me the arc (air gap
>>>>>resistor) would be a great, sudden, resistance that would indeed draw
>>>>>a large current spike.  Part of me thinks the opposite is true - for
>>>>>which I have no basis!
>>>>>
>>>>>I was not aware that common bulbs had a fuse either, I thought the
>>>>>filament IS the fuse.
>>>>>
>>>>>My interest in this has nothing to do with Insteon devices, it has
>>>>>more to do with what I can do to protect the circuit for devices I
>>>>>install, if the theory is true.  It may explain some anomalies I've
>>>>>experienced with security devices.
>>>>
>>>>The tungsten-arc is for real. The built-in fuse is also. If you hear a
>>>>"pop"
>>>>and see a bright flash, you're buying cheap bulbs. If you hear a "poof"
>>>>and
>>>>notice a bit of a flicker before darkness descends, your bulbs are fused
>>>>(even if cheap).
>>>>
>>>>The inrush current for an incandescent is about 10 times the current
>>>>once
>>>>the filament has warmed to its normal temperature. For a 100W bulb this
>>>>means an inrush at turn-on of +8A. The "fuse", if any, built in to the
>>>>wire
>>>>leading from base to the filament should withstand the inrush but blow
>>>>before a 15A breaker is tripped by a tungsten-arc.
>>
>>
>>>Come on...  This is all like discussing how many angels can dance on the
>>>head of a pin...
>>>
>>>In reality, don't most folks buy light bulbs at Home Depot, Lowes,
>>>Target, Walmart, (or at their local food store if they ran short)!
>>>
>>>I doubt that 99.9999% of the folks would buy "fused bulbs" vs "unfused
>>>bulbs" but will buy what's on sale..  Do you all not have a life?
>>
>>
>>The fundamental question for me is whether or not light bulbs can
>>cause equipment damage.  And no, I have no life.
>>
>>
>>
>>--
>>
>>-Graham
>
>
> Yes, a failing incandescent lamp can cause a current surge if the filament
> arcs as it falls apart.  That's been well known for years.  Incandescent
> dimmer manufacturers usually handle the situation by inserting a small
> impedance in the output circuit to protect the solid state parts which, of
> course, act faster than the thermal fuse in the lamp.
>
> General service inandescent lamps are gas filled and fused.  That's because
> when gas-filled lamps were developed in 1913, manufacturers learned quickly
> that an arcing filament was bad for business as it caused lamps to shatter,
> bases to melt and sparks to fly around.
>
> Terry McGowan
>
>
I knew that UK bulbs at 230V would arc and had fuses but until recently
I didn't think it was a problem in 120V bulbs. Where is the fuse hidden?

--
bud--