Scott, That appears to be a high resistance connection and not an arcing fault of any type. The AFCI device will trip for this type of fault only after the fault has progressed to a line to neutral, line to ground, or neutral to ground fault. It may or may not progress to a point where the AFCI will trip before the building is on fire. Will the AFCI have a better chance at detecting this fault before a fire starts than would a standard OCPD? Yes, it would. Don
An unusual looking receptacle. There are no screws to speak of (except for the EGC). It looks like what someone else here at ECN appropriately referred to as a "push and pray" type. I disected one of these receptacles to see just how much contact area was made between the #12TW wire I used and the contact points in the plug...appalling
Mike (mamills)
[This message has been edited by mamills (edited 02-27-2003).]
Is it just me or does that green screw look a little loose?
I've never seen an outlet like this. NEC should start spec'ing a minimum contact area to eliminate device like this. I'm starting to see a lot of spring type wired devices that look really nice. They probably save a lot of time and $$. When I see pictures like this I have to reconsider their use.
So I have a 12AWG plugged into the back of this with some spring terminal that engages the wire on maybe one side with only a small amount of surface area. Then I plug in my 12AWG cord from my wall AC unit. Right! I love the smell of plastic burning in the morning.... smells like... Er...uhm....UL listing?
Isn't it like running 1" water pipe, dropping down to 1/2" and then going back to 1".
Isn't this one reason the code requires electrical boxes? To contain failures like this so it doesn't set the house on fire. As I understand it (I'm one of those infamous electrical engineers) the NEC code is written such that, if complied with, a single failure like the above will be caught before it leads to a bigger failure (like the house burning down). Layers of redundancy, to improve safety.
This picture shows a receptacle with burned off contacts, and it was on a display table at one of my seminars.
Yes, the EGC was loose, and the use of 12 AWG is no longer permitted for the "push-in" types of connections.
I believe that UL stopped listing that product quite some time ago. The use of a box for enclosing a receptacle is usually the way in which it gets installed. A box does help to keep the "fault" contained within the box, that's why we have certain rules that limit open gaps and flush .... etc.