Andy Dingley wrote:
On Tue, 14 Jun 2005 09:55:40 +0100, David Hearn
wrote:


How then are screw terminals acceptable?


A screw point is not terribly big, so I wouldn't expect it to remove a
significant amount of oxidation when screwed up


It's because they're not very big. Small area leads to a high pressure
and good gas-tight joints. However this also means poor mechanical
strength. A screw terminal with a separate slipper pad under the screw
terminal gives a better mechanical connection, but the pressure is low
and they're not gas tight. Take your pick.


But whilst a small area will increase the pressure of the joint and
improve the gas-tightness of it - it also means that the area of contact
(and therefore electrical conduction) is smaller meaning it heats up.

I guess a lot of this is theoretical and academic. If it works in
practice then its fine - which I guess they all do, else people wouldn't
be allowed to use them.

D