14ga
wire was used on 2Kw
Altman Fresnels. It's high temperature heat
wire and can carry a higher amperage.. heat
wire loading.
Ferrules is a very good note - you never want to twist a screw onto a
strand of
wire - could break it, and otherwise with expansion/contraction under load cause it to
settle causing a now loose
terminal.
Springs while a good observation I don't think much a factor - too little surface area in the problem to loose temper. But that said, well stated though and I always compare tention with seating the lamp in tension in being a factor. Initial photo - I see your
point in discoloring of the spring on this
terminal, but not worried.
Moot
point is this the hot or
neutral terminal and or
plug mis-wired.
Loose
terminal screw for connecting
wire to lamp
base.... appairent -
wire settling or lack of
ferrule or in general not tensioned, and perhaps not re-tensioned after use. (expansion and contraction.)
Interesting the
wire out of the
terminal welded solid - never seen that before! Slight contributing factor is proper stripping of the
wire in not nicking or pulling off strands of
wire. Given the "Skin
Effect" of conductance in
wire, this mistake can cause an added heat/resistance to
current flow.
(John Carter...
Emery cloth too rough to use, Chrocus cloth and treat the bright work with contact cleaner in other post today.) Do not clean either new or abused lamp
socket or pins of lamps with
emery cloth! It's a starter grit and fine for say the swivel pole to a
followspot stand. Too rough for an electrical connection. And also you need to treat the fresh bright work!
"Have the fixtures you've repaired with factory parts been failing as well or are the original
tails the only ones that are giving you grief?" Good question mnicolai