nuckolls.bob(at)cox.net Guest
|
Posted: Sat Sep 13, 2008 10:03 am Post subject: AC vs DC ratings???? |
|
|
At 01:28 PM 9/13/2008 -0400, you wrote:
Quote: | Since there is no reference to DC switch ratings above, does this mean
that the DC switches are immune to different load types and L, T, & H ratings?
What, may I ask, is the difference between a DC switch and an AC switch???
|
Roger, check the article at:
http://www.aeroelectric.com/articles/Switch_Ratings.pdf
ALL switches have CAPABILITY in either DC or
AC systems. Not all switches are RATED for all
applications . . . especially if one limits their
enlightenment to the tiny print on the side of the
switch. There's not enough room to state the full
constellation of a switch's capabilities in that little
space. So what's a mother to do? Everyone prints
ratings on the device that address the majority of
applications where that switch would be used. Service
in household and industrial AC line operated appliance.
Does the lack of DC numbers mean that the device
has no capability in DC operations? Not at all.
But in spite of publication of engineering data there
are individuals who cannot or choose not to
interpret that data in useful ways. Such is the
case for the author of the article in Van's Air Force
newsletter that prompted the article cited above.
Yes, there ARE switch designs that will exhibit
optimized service life in DC or AC applications.
However, the fact that any given switch is not
optimized for one service or the other does not
mean that it does not offer useful service in our
airplanes.
Because of a very low duty-cycle in light aircraft,
ratings are only loosely tied to suitability to task.
Failure of a switch in our airplanes is more likely
to be related to environmental conditions as opposed
to service stresses.
Bob . . .
| - The Matronics AeroElectric-List Email Forum - | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|