Arc Fault Detection Device!

[OnlQQker]

These are going to become the norm aren't they?

I've been reading this https://electrical.------.org/cours...onsumer-guidance/arc-fault-detection-devices/

I was fixing the 21v motor on the Dyson this morning, and as usual my mind decides to wander.

For years I've come across scorch marks in lofts, behind skirtings, light fittings etc, etc, etc. Where it's always been the same thing, a lose connection or decayed wiring, leading to the plastic around it melting, and scorch marks around that etc.

When I first come across it many moons ago, I told the Herbert I was doing the job for to get an Electrician in and get the place rewired.
On my return some weeks later, the electrician had just fitted a new junction box and 1 length of cable.
The other scorch marks around other areas of just the loft, didn't seem to concern him? Then he told me this Herbert had asked him to just do a cheap repair!

In my annoyance I said to this Herbert that he will need to find another Builder because I didn't want the job, but he was adamant I was to do the job because I'd priced it up for peanuts.

Anyway He made a cup of tea for me and I walked out into the garden, whilst He went in to meltdown mode trying to ask neighbour's if he could put freezer stuff into there's.
I told him their was no need for this as parts could be kept going and temporarily power kept going.

But as I'm looking up at the roof, it's obvious to me it's joined to exactly the same house as next door, just divided in half and separated by a 9 inch wall, and a rather badly built firewall in the loft.

Now I'm no expert in this field, but I wouldn't be to happy sat in a house watching the movie 'Inferno' whilst you've got the real thing going on next door!

My point is, these needed inventing years ago to be honest, but the problems they will detect is going to be on a colossal scale, will it mean even pulling a plug on a boiling kettle could trip it?



Any experience's with these so far greatly received?

 

[DPG]

These are going to become the norm aren't they?

I've been reading this https://electrical.------.org/cours...onsumer-guidance/arc-fault-detection-devices/

I was fixing the 21v motor on the Dyson this morning, and as usual my mind decides to wander.

For years I've come across scorch marks in lofts, behind skirtings, light fittings etc, etc, etc. Where it's always been the same thing, a lose connection or decayed wiring, leading to the plastic around it melting, and scorch marks around that etc.

When I first come across it many moons ago, I told the Herbert I was doing the job for to get an Electrician in and get the place rewired.
On my return some weeks later, the electrician had just fitted a new junction box and 1 length of cable.
The other scorch marks around other areas of just the loft, didn't seem to concern him? Then he told me this Herbert had asked him to just do a cheap repair!

In my annoyance I said to this Herbert that he will need to find another Builder because I didn't want the job, but he was adamant I was to do the job because I'd priced it up for peanuts.

Anyway He made a cup of tea for me and I walked out into the garden, whilst He went in to meltdown mode trying to ask neighbour's if he could put freezer stuff into there's.
I told him their was no need for this as parts could be kept going and temporarily power kept going.

But as I'm looking up at the roof, it's obvious to me it's joined to exactly the same house as next door, just divided in half and separated by a 9 inch wall, and a rather badly built firewall in the loft.

Now I'm no expert in this field, but I wouldn't be to happy sat in a house watching the movie 'Inferno' whilst you've got the real thing going on next door!

My point is, these needed inventing years ago to be honest, but the problems they will detect is going to be on a colossal scale, will it mean even pulling a plug on a boiling kettle could trip it?



Any experience's with these so far greatly received?

They are pretty clever micro-controlled devices which are programmed to respond to the signature of sustained arcs. Unplugging kettle will not trip one.

Obviously they won't be perfect though.

 

[snowhead]

But as I'm looking up at the roof, it's obvious to me it's joined to exactly the same house as next door, just divided in half and separated by a 9 inch wall, and a rather badly built firewall in the loft.

Now I'm no expert in this field, but I wouldn't be to happy sat in a house watching the movie 'Inferno' whilst you've got the real thing going on next door!

You've never been in older terrace houses then.?
Originally they either didn't have any dividing wall in the loft /attic or only had half a wall in single brick.

It's only in more recent years that Mortgage lenders have been insisting on a full dividing wall.
I believe new builds have a full fire break right up to the roof tiles, unless of course it's one of the many notorious national new house builders, in which case the fire break will be in a bag thrown under the loft insulation.

 

[OnlQQker]

You've never been in older terrace houses then.?
Originally they either didn't have any dividing wall in the loft /attic or only had half a wall in single brick.

It's only in more recent years that Mortgage lenders have been insisting on a full dividing wall.
I believe new builds have a full fire break right up to the roof tiles, unless of course it's one of the many notorious national new house builders, in which case the fire break will be in a bag thrown under the loft insulation.

I've built firewalls in old terraced houses, I was always thrown by the roof batons, these continue through to every house.

Then of course there is the purling timber, this does exactly the same in a lot of cases, carries through.
And though it is possible to build the firewall right up to the top and angle bricks/blocks, it's never 100%

But I guess it adds a lot of protection, it looked like it may of worked on an old cottage down by the pier in Minehead that I walked past a few times last week, But then again the fire service down there were on it in seconds.

Historic Minehead cottage wrecked by early morning major blaze

FIRE investigators have confirmed the cause of a blaze which ripped through a 400-hundred-year-old West Somerset cottage today was accidental.

www.wsfp.co.uk

 

[littlespark]

The risk of fire spreading through terraced houses the same as old tenements where there isn't a fire break between the ground floor, first floor, second floor etc.... or old victorian houses chopped up into flats with nothing but the original lath and plaster ceiling and very old floorboards.

the technology for AFDDs is fairly recent, as explained.... but we have been periodically inspecting properties for years now, where any scorch marks like this would be found and repaired.

Haven't we?

 

[pc1966]

Scorch marks above lights are probably the result of decades of filament lamps heating things.

AFDD will probably become the norm in 10-20 years, rather like RCBOs are now, when the cost falls and regulations push harder.

I am sceptical of how effective they are in practice, relative to the number of fires due to overheating joints or faulty appliances that go up without an arc signature, but once they become cheap enough and if they start to have other added value (such as Bluetooth load monitoring, etc, which ought to be practical at little added cost given they already have sense coils and microprocessors, etc, anyway) they will make sense. Even if it is only a small portion of fires they stop.

 

[OnlQQker]

Sometimes I wish I had never messed about with taking apart a plug socket with a pair of scissors when I was 7 years old. The belt was something I couldn't put into words, and that alone should of put me off electrics for the rest of my life, but it done the complete opposite, the shock woke me right up.

Fast forward 11 years, Willis Dawson had a job at Sanderson sub station, whether it is still there I don't know, it was in the middle of no-where.
For reasons that I kind of understand today (but wont go into details as it's boring) was sent to this sub station to dig and concrete a new concrete pad for whatever reason they needed it for.
I pulled up with a lorry, small lorry like this but a lot older.

I had 4x2 sawn timber, 2.4m long x 10
one tonne of ballast, 6 bags of cement, a petrol mixer and sheets of ply.

The job was within the cage, right next to these things

I'd totally forgot about the shock I had at 7 years old, I never even gave it a thought if I'm to be honest.
I unloaded the 4x2 and propped it up against the outside of the cage, then the rest of the gear from the lorry.

This chap then pulls up in a car, little did I know he was from the Electricity board and was in charge of that sub station.

He went nuts, so much so I loaded everything back on the lorry and took it back to the yard.
I was sent straight back out to the job with a Willis Dawson foreman following behind in his car, when we got there the foreman and the electricity guy had a face off, I don't know who won, but I was left alone and did exactly the same thing again. Yet this time carrying it inside the cage and propping it up where ever.

And this is where things get interesting, the foreman had come over to me when I was sat in the lorry waiting, he said to me, 'keep everything low to the ground, apparently electricity can jump and we''ll have to get somebody else from Willis Dawson to do it if it jumps on you'
But I didn't have the understanding to connect the dots, I was just a groundworker, shovel and pick axe and a mentality they had bred into me, 'if it's hard be hard with it'

The thing is though, even though I propped up these lengths of 4x2, whilst the foreman and the electrical board bloke sat in their cars with a rather uncomfortable, transfixed stare like they had seen a ghost, or about to see one, I carried on regardless with my pick axe and shovel.

Something did happen though, 10 inches down my pick axe hit the biggest cable I had ever seen, it was bad enough that suddenly I remembered the shock I had at 7 years old.

The damage was not slight, and I should of told the foreman, but I never did, instead I laid some heavy duty builders membrane over it and concreted it in.

So I guess I've gone away from the main subject a little, and in a way I'm admitting that not only can builders me a pain in the ar*e messing about with wires in houses, some messed about with wires in a sub station.

I would of gone into electrics at 16 if I had the choice, but my Dad was adamant I was put with the groundworkers, and I don't want to appear rude to groundworkers, but those guys lived for beer and digging back then. Ever dare to say them, 'I can't dig that it's to hard' and you'd be at the bottom of the trench with them filling it in on you.

I wonder sometimes if things have changed now with the Groundworkers, perhaps they drink pimm's now and paint their nails in their spare time?


I'd like to learn more about AFDD's and more so how they are performing after installation, I can't get hold of that information as we're not ahead in time enough.

 

[pirate]

John Ward has a series of videos on AFDDs which are worth a look

 

[pirate]

Oh...I just got a trophy! Thanks to you all for liking my ramblings!

 

[nicebutdim]

I wonder sometimes if things have changed now with the Groundworkers, perhaps they drink pimm's now and paint their nails in their spare time?

They have dump trucks and diggers now. They drive/cut/dig through anything that gets in their way and stop for no one.

 

[OnlQQker]

John Ward has a series of videos on AFDDs which are worth a look

Just started my journey watching Mr Wards video, thanks again for the suggestion.

The top comment on the video is interesting, I didn't realise how long these devices had been about...

But I have to agree with the top comment on part 3.