neutral caught fire

[bigbob]

What would cause the neutral tail incoming to a domestic cu to catch fire 25mm. Loose connection ? i dunno .

bigbob

 

[PompeySparks]

Yes, very likely a loose connection or the tail may have had a lot of dirt on it when it was terminated (high resistance joint)

 

[Jaymack]

If only the Neutral connection is involved then you are correct: - loose connection.
Jaymack

 

[bigbob]

ty for prompt answers. it did not blow service fuse 60a does this still look likely problem?

bigbob

 

[PompeySparks]

Yep - most likely the loose connection with a dirty one being an outside possibility (also some of the neutral tail's insulation may have been clamped in the tail, causing higher resistance!)

 

[bigbob]

ahh! ty pompey 657

 

[PompeySparks]

No probs!

 

[Adam_151]

(also some of the neutral tail's insulation may have been clamped in the tail, causing higher resistance!)

Reminds me of one of the worst wired plugs I ever saw, insulated conductor clamped in the screw, then a tail of stripped wire reached round and was pressed against the top of the screw, luckily it was only a portable televisoon, so no real current draw.

Interesting discussion on why it always seems to be the neutral that burns up here: http://www.theiet.org/Forums/forum/messageview.cfm?catid=205&threadid=9343&highlight_key=y&keyword1= though it didn't really go anywhere, personally I guess its probably due to the greater respect people have for phase, and they subconciously give the phase the extra turn and not the neutral

 

[PompeySparks]

'personally I guess its probably due to the greater respect people have for phase, and they subconsciously give the phase the extra turn and not the neutral'

Agree Adam - it shows how widespread the misconception is that there is 'no current' in the neutral (confused with 'no voltage' in a correctly tied down neutral - the current in the neutral should approximately equal the current in the phase in a single phase supply)

I have found more than a few terminations in plugtops (and fixed wiring!) where the person doing the work did not bother to strip the insulation but just terminated the un-stripped ends!

Presumably they thought the terminal screw would sufficiently pierce the insulation and make a solid connection...

or more likely, they just didn't give a 4X!

 

[Qedelec]

Hey Pomp, now you may have hit on an idea there.
Maybe we can persuade manufacturers to modify the terminal screw so that it cuts/peirces the cable, could save us a lot of time.