The mystery of the arcing cable
Added 2021-10-05 17:27:21 +0000 UTCAn extension lead and plug in thermostat that may or may not have been involved in the cable suddenly spewing a flame out of its side.
https://www.youtube.com/watch?v=ktNxF5SmZGg
It turns out it wasn't as sinister as it sounds. I also took the thermostat apart and explored the circuitry. No schematic though, as it breaks down into distinct modules with just a small amount of discrete components.
Comments
Not really between live and neutral as it tends to look like a low load. Between live and earth the RCD/GFCI will trip.
Big Clive
2021-10-09 04:43:39 +0000 UTCI'm in the US and have never heard them called that. We call them box cutters or utility knives.
Circuitmike
2021-10-07 20:03:16 +0000 UTCIs there a cheap gadget you can plug into an extension cable that can detect the early signs of a carbon trace before it starts shooting plasma?
Christopher Wenham
2021-10-07 18:56:23 +0000 UTCIt's way too hot.
Big Clive
2021-10-06 23:58:36 +0000 UTCIn mine the Grey ribbon cable not soldered, just pulled out all the wires, I had a timer that looked a bit like this from the 1980s it included a simple switch on/off "then revert to timer", not like the new ones that you have to press more than once and they override the timer. Odd that the ribbon cable wire just pulled out of the solder and had not whetted to them. Reason for taking it apart was that the internal battery memory backup had failed. I have not found a timer like it since. John
John Harrison
2021-10-06 22:35:57 +0000 UTCWow 19 degrees in Clive’s house, that’s positively tropical!
2021-10-06 07:29:20 +0000 UTC0.75mm with 13A fuse.
Big Clive
2021-10-06 00:45:35 +0000 UTCLooks like only a 6A cable, I wonder if a 2kw fan heater was involved, finding the weak spot.
Graham Eida
2021-10-05 23:29:41 +0000 UTCVisual examination is probably the most important part of a PAT test
Mark Holder
2021-10-05 21:02:46 +0000 UTCUK Stanley Knife == US Box Cutter. TBF that mains lead looked like it had received a soldering iron burn. Mentioning no names of course. Leads are important for safety - and also mechanically vulnerable. I don't think the Fisher Price PAT testers do L-N insulation. Maybe that should change?
Mike Page
2021-10-05 20:10:43 +0000 UTCThey call them Laurel blades in the US lol
Ymir the Frost Giant
2021-10-05 19:35:40 +0000 UTCPossibly but that usually results in a break rather than a short but it does happen
Mark Holder
2021-10-05 19:24:48 +0000 UTCOr the cable may have been "crimped" under a heavy object or trapped in/under a door.
Tokkan FX
2021-10-05 18:54:17 +0000 UTCSocaplex sorry
Mark Holder
2021-10-05 18:29:34 +0000 UTCIt was a heater, as mentioned in the letter, so it makes sense that it would maintain an arc.
Paul Schuur
2021-10-05 18:27:21 +0000 UTCYep, I gave up telling "technicians" that it's also bad practice to use a Stanley knife for stripping cables for much the same reason. They soon learnt though. They played find the faulty socaplex most of the day.
Mark Holder
2021-10-05 18:26:45 +0000 UTCI think the generic term is "box cutter" blade
Gerry BVR
2021-10-05 17:41:23 +0000 UTC
