Domestics - 2 way switching - Good deed for a bank holiday.

[SUNRAY]

One of the neighbouring bungalows changed hands 3 or 4 months back, single mother with 2 under 10 (my estimate) girls, lovely friendly woman fitted right into the immediate neighbours friendship. End of June we invited neighbours for afternoon drinks and snacks including them but they were already busy. We heard about her recent life and the unfortunate reasons they moved here.

Tonight we heard the scream (~50m away) and thought it was animals, 10 minutes later a knock at our door by her immediate neighbour. The daughter got a shock off a light switch now total power off and waiting for an ambulance.

Poor kiddie still hysterical as I looked at the scorch mark going at least 2 feet down the wall from the switch, the girl had similar marks on arm and clothes.

The switch rocker moved but obviously didn't do anything, she produced a metal switch as a replacement.
A smaller black burn mark on the ceiling each side of the chrome MR16x3 halogen/toroid fitting which I knew to be left by previous occupants. I removed the fitting and switch but had never seen so much damage on a lighting circuit before. the cable at both was too badly melted to re-use and badly blackened, giving the switchdrop a tug it felt like it was loose in the metal capping.

Just inside the loft I found three 6 terminal JB's and traced the light cable to the one wired like this:

And quickly able to disconnect the feed from the adjacent JB so power could be restored to the rest of the property and added a strand from 7/0.2mm wire for the lighting fuse. I was able to readily grab an offcut of 3C&E and a used batten holder from home, still containing the CFL. I was able to pull the new cable into the wall and wired the switch and more easily replace the cable to the light (again with 3C&E).

By then Mum and daughter had gone in the ambulance and the other girl in bed and a neighbour babysitting, I reconnected the power feed but quickly found the other switch had failed, from home I grabbed a 2G switch (only single required) and fitted it.

Up until that point all quite unremarkable, except...

Sunray scratched his head for a few moments Wondering what I'd done wrong as only one combination of switch positions worked, my led screwdriver soon told me yellow and blue required swapping.

Getting home, my rough sketch convinced me it was wired incorrectly before I got there.

Oh well that was my good deed for the day

 

[securespark]

It was indeed.

But what was the cause of the shock? And the black marks? And burnt cable?

But most important of all how is the little girl?

And is the house a rental or a purchase?

How did this mess slip through?

 

[SUNRAY]

It was indeed.

But what was the cause of the shock? And the black marks? And burnt cable?

But most important of all how is the little girl?

And is the house a rental or a purchase?

How did this mess slip through?

The plastic lapping of the toroid very crispy and dark, a patch of it is burnt and appears to be the source of the blackened ceiling, this is only a guess but I suspect it overheated and shorted turns, I don't know if the light was being switched on or off at the time. I'm guessing it is more of a burn shock than electric shock but I don't know.
The bungalow was being rented but this was a sale. She does know the 'fuse box needs to be replaced' as part of the survey/purchase... which I imagine will be sooner rather than later now.
The fusebox has an upfront RCD which the light circuit prevented resetting.
I left not very long after the ambulance, her car isn't there today so not seen anyone to get an update.

 

[endecotp]

Scorch marks on her arms and clothes!!! That sounds more like a lightning strike than 240V.

Is there a nail where the 6A lighting fuse should be?

 

[SUNRAY]

Scorch marks on her arms and clothes!!! That sounds more like a lightning strike than 240V.

Is there a nail where the 6A lighting fuse should be?

No there was the remains of the fuse wire which I suspect may have been a size up from 5A but not dramatically so, particularly as the previous owner (when he passed - during early lockdown but unrelated - his retired daughter rented it out until recently EDIT: to pay off her mortgage according to Mrs S) loved MR16's which I believe accounted for every light in the property and some toroids have a high inrush current, so going up a size has been a common fix.

 

[SUNRAY]

OK so I've received a critical private message regarding this thread, from a smart Alec (EDIT: From this site) who included:
"Oh for pity's sake I'm sure I'm not the only who knows the fuse does not limit the current under fault conditions. Why do you make that silly mistake"

I'm aware of fault currents and not making any such mistake, silly or otherwise.

 

[ericmark]

I have in the past tried to do the good deed, and one does have a feel good feeling when it works out, and also why did I ever start this when it goes wrong.

Remember in the Falklands one going wrong, clearly joints in the loft space, and no access. And that why did I ever start this.

 

[SUNRAY]

I have in the past tried to do the good deed, and one does have a feel good feeling when it works out,

This one is a 30's widowed single mum with no power and an injured youngster at 8pm on a bank holiday,

and also why did I ever start this when it goes wrong.

Oh yes, certainly been there.

Remember in the Falklands one going wrong, clearly joints in the loft space, and no access.

and crazy amounts of cable testing to try to workout what goes where... and why

And that why did I ever start this.

 

[ericmark]

Tomorrow back to basics, volunteering at local heritage steam railway. We work in pairs, so we can help each other get up again, I am about the youngest at 74.

 

[SUNRAY]

They kept the girl in for observations and mum stayed, they came home last night, she has a burns dressing covering her palm and nearly to her elbow but as bright as a button. They came over say thanks and tried to pay. The other girl went home with the neighbour overnight and all day.

 

[SUNRAY]

There has been a strange car on the drive during last week, including overnights. We kind of assumed a boyfriend.

He popped over to us this morning and introduced himself as her cousin and electrician from Cheshunt, to return the used batten holder and 2G switch and thanked me for helping out, he seemed keen for me to see what he has done so I went over. For an all RCBO CU replacement quite a tidy job bearing in mind the limited length of existing neutral wiring, all new light fittings and accessories, all of which were there (awaiting his presence) when the bang happened.

Quite brought a lump to my throat.

The little girl of 7 was keen to show off her missing teeth and scars in that order - "Mummy says I mustn't scratch them." Red patches in the palm, her wrist and near her elbow but look to be healing well as young flesh does.