Re: I think they've done it again.

["Robert Green" <ROBERT_GREEN1963@xxxxxxxxx>]

"Dave Houston" <nobody@xxxxxxxxxxxx> wrote in message
news:44970646.218243968@xxxxxxxxxxxxxxxx
> Turning it off and on rapidly can blow a bulb. I recently had to retire an
> LM14A that started flashing full on as it dimmed to off. I replaced 3
bulbs
> in a few weeks time whereas I seldom had to replace any bulbs before this.
I
> heard from someone else who experienced the same thing.

I've had bad runs of bulbs that have blown switches when they popped.  Some
detached from the screw base completely.  Do you still have the LM14A?  Did
you inspect it internally for blown components?  I just had a bad batch of
bulbs (4 to be exact - from a four pack).  Not only did they blow, but they
killed the local (but oddly enough not the remote) control of the wall
switch twice in a row before I realized it was the bulbs.

Getting back to blowing bulbs, I thought a triac only "chops" the existing
waveform?   So, how does it burn it out?  The dimming flash?  I can flick a
manual light switch on and off all day without cashiering a bulb.  Is there
something different about the way a lamp module switches that presents a
different inrush current scenario than a mechanical click switch?

I was just wondering whether you got part of the same bad batch of bulbs
that I did and they partially blew your LM14A.  Then, the rest of the bad
bulbs burned out prematurely (or spectacularly, as mine did) and threw
"suspicion" on the LM14A.  My security system flashes the house lights from
full on to full off and those bulbs don't explode or seem to burn out very
much faster than bulbs that aren't on the flash circuit. I'll bet I could
rig a test with either an appliance or lamp module and count the number of
cycles until failure pretty simply.

I'm not doubting that you lost a string of light bulbs, I'd just like to
understand how that's electrically possible without there being a huge surge
on the whole house line or some overvoltage getting to the filament.

Again, not trying to be a prick, just trying to understand *how* an X-10
switch can blow a light bulb.  It's always been the other way around for
me - a bulb "pops" and takes the *switch* with it.  As far as I know (and
that's not very far!) filaments fail due to fatigue from the constant
thermal cycling causing plastic deformation of the hot filament each cycle.
I seem to recall that's normally hundreds of cycles if not thousands,
although I've yet to find a specific claim as to number of cycles.   I did
find this, however, from a list of light bulb tips:

Light bulbs Sometimes Get Brighter When Something Else is Turned On and also
Burn Out at an Excessive Rate:

a) This usually means that you have a broken or poor neutral connection,
usually in the main panel, or sometimes in a sub-panel if you have any
sub-panels. Be sure that screws holding down wires in your fuse boxes /
breaker boxes / panels are adequately tight. If you are not up to this fix
or it fails to correct this situation, call an electrician. This is a
dangerous condition that must be fixed urgently.

http://www.arcadianlighting.com/troubleshoot-lamps.html


While I obviously don't think this is the case with your LM14A, I can easily
see it being the problem Insteon's facing, at least with some of the lamp
failure problems.  We've seen, time and time again right here in CHA, that
when faced with a lack of a neutral at the switch, people become incredibly
creative in finding ways to get a neutral to that location.  Lots of times,
it's via some very, very dubious wiring practices.  If you pulled a neutral
to an Insteon switch that wasn't properly bonded at the panel, it might
cause some serious issues.  I suspect that it's the cause of at least *some*
of the trouble reports.

--
Bobby G.

>
> "Robert Green" <ROBERT_GREEN1963@xxxxxxxxx> wrote:
>
> >Also, how can a defective switch "blow" a normal bulb?  Sounds a little
> >"off" to me.  Bulbs should only do that if presented with a voltage way
over
> >their rating.  I suspect miswiring, perhaps bad enough to feed 240 into a
> >120VAC device, at least in the blown bulb reports.
>