[SML] Mundane Lighting Questions

[Dale Farmer]

Probably just worn out sockets.   The center contact gets really hot and 
that bakes out the sproing in the spring.  so it isn't making good 
contact and it starts arcing and sparking, burning the contacts making 
the conduction worse.   the only real solution is to replace the socket 
and toss out any bulbs that have burned center contacts as burned lamp 
contacts are contagious.  If you can't replace the sockets, toss the 
fixtures.  There is two different versions of the socket out there, same 
actual lamp socket, but the mounting holes are different, so the lamp 
ends up rotated and it messes up the beam pattern.   Can't speak to 
current availability as I don't fix fixtures anymore.  Maybe flog them 
on ebay as "vintage lighting fixtures" to interior designers.

Dale

On 9/21/2023 2:36 PM, Steven Mclean via Stagecraft wrote:
> First,  I owe the list an apology.  You may remember that I was trying 
> to sort out what was going on in the theatre I "inherited" regarding 
> dimmer assignments (whereas there were circuits labled 1 through 120, 
> but only one rack of 96 dimmers feeding them.
> 
> Nothing exotic was going on.  It turns out that when the "new" dimmer 
> rack was installed in the facility, they didn't have the wherewithal to 
> do dimmer-per-circuit (which was the norm at the time) for all 120 
> existing circuits, so once they got to 97, they connected that circuit 
> to dimmer 1 (in addition to the circuit labeled "1") and 98 to dimmer 
> 2...etc.  I had a conversation with the guy in charge of the facility 30 
> years ago, and he put into my head that "dimmer doubling" which was new 
> at the time) was going to be used.  It apparently was not.
> 
> Now I am puzzled by another problem. We have OLD Fresnel instruments in 
> the space and I have run across a pile of 8"  Fresnel fixtures  that 
> seem to have the same problem. The instruments check out just fine with 
> the continuity tester.  Continuity between the tines of the plug & the 
> appropriate contacts in the socket/bases, But when a BTL lamp is put in, 
> it seems loose.  the spring contact at the bottom of the socket doesn't 
> seem to press reliably against the bottom contact of the lamp, thus the 
> lamps are energized intermittently (or not at all)
> 
> Is there a DIFFERENT  lamp that these should be using (one with a 
> slightly deeper base) or is it possible that the ceramic socket bases 
> need to be replaced?   Some of them almost look new (as if they had 
> already been replaced recently)...is it possible that some 
> predecessor secured the WRONG base/socket?
> 
> -- 
> Steven J McLean
> 515-480-8461
> stevenjmclean at gmail.com <mailto:stevenjmclean at gmail.com>
> smclean at grandview.edu <mailto:smclean at grandview.edu>
> designandtechtheatre.wordpress.com 
> <http://designandtechtheatre.wordpress.com>
> 
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