Re: halogen lamp on x10

["Robert Green" <ROBERT_GREEN1963@xxxxxxxxx>]

<bcboy@xxxxxxxxxxxxxxxxxx> wrote in message

> I have (not through my own actions) recently come to own one of those
> very cheap six-foot tall halogen torchiere lamps. It put out a ton of
> light, but it failed after about two months.

Might have been too high a wattage bulb, a poorly ventilated shade, a low
ceiling with limited airflow or a cheap design that caused heat to build up
around the lamp.

If there is a dimmer in the lamp, there's a possibility of problem
interactions with the X10 lamp module dimming circuitry.  There are so many
variations in lamp circuitry design, it hard to say what will work and what
will not.

How did the bulbs fail?  Their condition is often a clue to the mode of
their failure.  IIRC, black and smoky is probably old age or a bad bulb and
greyish but clear means a cracked bulb, possibly from finger oil deposited
on the quartz.   Even with the bulbs to examine, it would be hard to
pinpoint the cause.

> I'm wondering if it's related to x10, or if this is typical of
> these lamps. The contacts with the bulb are oxidizing. When
> I removed the bulb a little pellet of oxidized metal fell from
> between the bulb and the spring-loaded
> contact. A bit of sanding restored the connection.

I'm leaning towards low ceiling, bad airflow.  These lamps reach a
temperature = the melting point of lead.  Sounds like it got hot enough to
melt some solder somewhere.  If it was pelletized, it was probably melted
into that shape, not broken off from somewhere.

> I owned one of these about 12 years ago, and it failed in the same way.
> In both cases I had the light on an external switch (an x10 lamp module
> in the recent case). I'm wondering if turning the light on suddenly
> could be causing this. If it's turned on at the base (instead of x10),
> it fades up because the "on" switch is also a dimmer.

Not likely.  Plenty of people bypass the built-in switch to insure X-10's
triac circuit won't interact badly with the built-in dimmer at switch
without ill-effect.  Improper cooling from bad design or sub-optimal
placement is likely to have much more effect.  Halogen bulbs have to be
allowed to get up to temperature.  They'll fail prematurely if you use them
in closets or other places where they're only on for a few minutes.

> Anyone else using an lamp module with one of these?
>
> I have some halogen flood lights that take the same kind of bulbs and
> are also on x10.

Are the flood fixtures able to dissipate heat better?  Are the outside where
it's always likely to be cooler?

> They work fine. No troubles. I don't know what the
> difference is. Perhaps the strength of the spring.

If the contact wasn't good, you would see flickering and maybe even hear
arcing noises.  It's hard to really tell how hot the lamps are getting
without Tempilsticks (basically crayons that melt at specific temperatures)
or a fancy gun thermometer, but halogens in enclosed places (like video
projectors) HAVE to be fan cooled or they'll burn up in short order.  Floor
lamps have a large radiant area to distribute the heat but the torchieres
are so tall they often trap huge pockets of heat right at the ceiling, where
heat naturally rises anyway.

Make sure that you test the tip switch in the unit and that the top has a
wire fire guard.  Those lamps have probably killed more people than Billy
the Kid.

--
Bobby G.