28 Nov
2011
28 Nov
'11
1:26 p.m.
[T]hat's not the point I was making. The
electrical parts -- the
contacts, are the same in the normal and the 'hot codition' ones, and
yet the former was rated at 6A and the latter at 10A. Why the
difference?
Now, I suppose the hot condtion ones could stand
the contacts running
hotter so they could carry more current, but IMHO if the contacts of
a connector are getting that hot, it's underrated.
Thoughts:
(1) In some cases it may well run hot even if the contact is good, if
it is thermally close to something that's _supposed_ to run hot (a
teakettle heating element comes to mind).
(2) What's the problem with running hot (even if due to poor contact),
if everything close enough to be affected is designed to run that hot?
It's a waste of power, and it also means there's a voltage drop across
the pin/socket. This mightcause problems.
(3) If something goes slightly wrong and it starts running hotter than
it should, it's better if everything can stand it until someone notices
and deals with it. The higher the device's draw, the hotter a poor
contact will run. In other words, it's basically safety headroom.
True.
My real qustion is that originally the 'normal one was rated at 6A, the
'hot codition' one, which is identically electrically, was rated at 10A.
Maybe the latter could carry more current becasue it could get hotter,
but I don't like it... Now, a lot of 'normal' ones seem to be rated at
10A, although they appear to be unchanged from the older 6A versions.
My first guess is that the original 6A rating as a very conservative one.
-tony