Re: BTR Lamp failures

"Islander" <islander@[EMAIL PROTECTED]
> wrote in message 
news:0evp6451fkj7qgtuv8097fqqtg8rt8j185@[EMAIL PROTECTED]
> We have 12 Stand 6"fresnels in our inventory. Age - 10 yrs old, same
> as the rest of our inventory.  This past year I am going through GE
> BTR lamps in these like crazy.  I use one specific brand from our
> supplier and never had any problems with them until 2 yrs ago when we
> relamped.  They all seem to blow when doing a lamp check when first
> firing up he board. They always fail with two black marks on he side
> of the glass in the middle and the filaments are rolling around in the
> glass.   No finger prints on the glass.  mainly cuz I use editors
> gloves to change them.
>
> I have taken to setting the patch for these dimmers to be 95% at full
> on the channel  but just blew another one the other day.  I have also
> set the focus slightly in from full flood on all fixtures so they lamp
> is back from a lens a bit. Still it blows.
>
> Other thing I note these lamps are getting very hard to get in and out
> of the sockets.  Hard even when they were new. The difference in the
> size of the two flanges is difficult to see when in the dark catwalk.
> My maglight helps but I don't have 3 hands.  <grin>
>
> Anyone else experiencing difficulties with this.??
>
> cheers
> Marv
>
The fact that they are getting hard to put in may mean that the socket is
getting pitted from arcing. The actual contact area is really small on
those
types of sockets and often they don't make a good contact with the l
amp base. This can cause the base to heat up enough to cause a failure
in the connection with the filiment. The result can be a failed lamp that
looks to be OK. You might want to change the sockets. I've been told that
some plases routinely replace the socket on fixtures 5000 watts and over
every time they pull a lamp that shows the slightest sign of arching.

I'm not sure if it could cause filiment failure as well.

David