The Electrical Contractor Network

ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

Books, Tools and Test Equipment for Electrical and Construction Trades

Page 1 of 2 1 2 >
Topic Options
Rate This Topic
#104459 - 02/27/03 03:50 AM Loose Connections Cause Fire Hazards
Joe Tedesco Offline
Member

Registered: 10/07/00
Posts: 3325
Loc: Boston, Massachusetts USA


Loose connections and the load on the circuit created enough heat to cause this damage that could cause a serious fire.
_________________________
Joe Tedesco, NEC Consultant

Top
2014 / 2011 NEC & Related Books and Study Guides
#104460 - 02/27/03 04:34 AM Re: Loose Connections Cause Fire Hazards
Electricmanscott Offline
Member

Registered: 01/12/02
Posts: 1478
Loc: Holden, MA USA
Ok you guys are going to hate me, but, would an AFCI have caught this?

Top
#104461 - 02/27/03 08:15 AM Re: Loose Connections Cause Fire Hazards
resqcapt19 Offline
Member

Registered: 11/10/00
Posts: 2209
Loc: IL
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
_________________________
Don(resqcapt19)

Top
#104462 - 02/27/03 08:42 AM Re: Loose Connections Cause Fire Hazards
mamills Offline
Member

Registered: 11/30/01
Posts: 739
Loc: Wharton, Texas, USA
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).]

Top
#104463 - 02/27/03 09:42 AM Re: Loose Connections Cause Fire Hazards
RSmike Offline
Member

Registered: 11/27/02
Posts: 130
Loc: Holland, MI USA
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".

RSlater,
RSmike

Top
#104464 - 02/27/03 10:45 AM Re: Loose Connections Cause Fire Hazards
wa2ise Offline
Member

Registered: 11/29/02
Posts: 771
Loc: Oradell NJ USA
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.

Top
#104465 - 02/27/03 12:07 PM Re: Loose Connections Cause Fire Hazards
SvenNYC Offline
Member

Registered: 08/19/02
Posts: 1685
Loc: New York City
Re: electrical boxes containing failures

That's an interesting comment and I can see where it would work with a metal box.

However how would a plastic box contain a flareup like that? Plastic melts and sometimes burns.

Are plastic device boxes made of a fire-retardant material? I'm not too familiar with them...have always dealt with and seen metal boxes only.

Top
#104466 - 02/27/03 12:10 PM Re: Loose Connections Cause Fire Hazards
Joe Tedesco Offline
Member

Registered: 10/07/00
Posts: 3325
Loc: Boston, Massachusetts USA
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.
_________________________
Joe Tedesco, NEC Consultant

Top
#104467 - 09/10/05 03:33 AM Re: Loose Connections Cause Fire Hazards
Joe Tedesco Offline
Member

Registered: 10/07/00
Posts: 3325
Loc: Boston, Massachusetts USA
Have any others that look like this one?

_________________________
Joe Tedesco, NEC Consultant

Top
#104468 - 09/10/05 06:07 AM Re: Loose Connections Cause Fire Hazards
sandro2 Offline
Member

Registered: 03/26/05
Posts: 49
Loc: philadelphia,PA
Question about afci breakers. Do they detect in line arcs. Example when a load is turned on?

Top
Page 1 of 2 1 2 >



ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals