Fuse box fire with photos

[bigdavs83]

Possibly overtightened screw on the neutral which has split the bar and over the years has eventually arced its way clear and hey presto up she goes! Seen it on 3 phase boards where the goon doing the maintenance just has to get the final tighten on the screw and splits the busbar 6 months later monitors and computers have smoke piling out of them cos there's no neutral path back to the db

 

[DPG]

Although I can see the logic if the plug is decent then the neutral pin should not move at all.
The plugs we use have the pins locked in place by little plastic hooks, However I have seen some really **** plugs.

The worst ones being those stupid clamp down type where you have to bend the wire around the pin and then a little nut screws down ontop to hold them in place.

The MK ones that use that method are good plugs. Daz

 

[Tiny Spark]

The MK ones that use that method are good plugs. Daz

Think the ones we tried were MK, Cant say I was approving.
You wrap the wire around which takes forever and fidly as hell then when you clamp the nut down the strands seperate and spill out of the side.

Duraplug is where its at

 

[brman]

I'd guess neutral at the plug for the stress reasons given and neutral at the board because it is a much smaller screw/clamp than the line which is normally a proper cage clamp in the MCB.
Just a guess though.......

 

[GLENNSPARK]

What are protex boards?? They sound rubbish

yeah they are..
check out how the breakers sit next to each other in the pics...

i had to replace an RCD on a protec last week...and it was the same...

totally crap boards these...
there were a lot of em fitted on the 16th...

 

[GLENNSPARK]

I'd guess neutral at the plug for the stress reasons given and neutral at the board because it is a much smaller screw/clamp than the line which is normally a proper cage clamp in the MCB.
Just a guess though.......

the terminal screws on these protec`s are seriously chud....
in fact the whole thing is a bunch of chud...

 

[Marvo]

I hadn't considered harmonics to be an issue on an electric shower....My
theory is that showers and immersions tend to be installed by jobbing plumbers - the little treasures!

In a single phase circuit, line and neutral will always be the same, won't they? Apologies if I'm taking seriously, something that was said in jest.

Apologies, I didn't read the post correctly, yes in a single phase supply it will be same. In these cases I guess it's a combination of an inferior connection method as already stated because the live has a caged clamp whereas the N is often directly under a screw. Secondly, especially in the UK I don't read much about a Neutral or loop impedance test being done, yes you do R1 + R2 but the neutral seems like it's pretty much exempt from testing under UK requirements so overtightened and undertightened connections are more likely to slip through the net on the neutral side.

 

[Geordie Spark]

Why is the Main Switch still closed ( piccies1 & 3 ) ??

 

[HandySparks]

Secondly, especially in the UK I don't read much about a Neutral or loop impedance test being done, yes you do R1 + R2 but the neutral seems like it's pretty much exempt from testing under UK requirements....

Yes, I've wondered about that for a while. Seems a bit of a dropoff to me that checking the neutral isn't required, apart from continuity of ring final circuit conductors. When I'm testing Zs, I'll often check the line impedance at the same time. It's a very quick test to do with my Fluke. I don't write the results down on the final EIC or EICR form because there's no space for it, but I'll check that the figure seems reasonable.

 

[uksparks]

I switched it off after taking these initial photos, believe it or not, the client had removed the front and switch the isolator off. I switched this off after i took the photos and also locked the isolator off and put a warning sign on it. I didn't get the job to fix it as they wanted it doing there and then and it was 4:30pm and I said I can do Friday, so day after next, and they didn't want that so not much I could offer really. I don't know about you but I personally wouldn't take on changing a board that late in the day when the light was starting to go. Not only that I needed my big steps to reach the high ceiling which I had not got with me.

 

[Geordie Spark]

I switched it off after taking these initial photos, believe it or not, the client had removed the front and switch the isolator off. I switched this off after i took the photos and also locked the isolator off and put a warning sign on it. I didn't get the job to fix it as they wanted it doing there and then and it was 4:30pm and I said I can do Friday, so day after next, and they didn't want that so not much I could offer really. I don't know about you but I personally wouldn't take on changing a board that late in the day when the light was starting to go. Not only that I needed my big steps to reach the high ceiling which I had not got with me.

Sensible lad.

That would have ended-up as a real ballache. Far better to start it in the daytime.

 

[dcelectrical]

ooh what a palaver, surely putting all the neutrals into a bit of chocky and feeding them into the bottom of the isolator would have done the trick, just get them to pay cash and everyones laughing. more beer moneyon a Friday.
I reckon the neutral gets it because of the flow of current is actually from the neutral back to the live and if I scratch my head a bit more I seem to remember something about conventional flow being the reverse of what we all think it is. although I just know that the black one has just as much bite as the red one. luckily have never grabbed a blue one as older and possibly wiser.

 

[DPG]

Can't see why the direction of current would affect things. Daz

 

[netblindpaul]

We are talking a.c. so the flow of current has nothing to do with it, think about it...

 

[Taylortwocities]

if I scratch my head a bit more I seem to remember something about conventional flow being the reverse of what we all think it is.

I think your head scratching related to DC theory. In the early days of electronics it was assumed that DC current flowed from positive to negative. Later they discovered that it flows from negative to positive. If electrons had been discovered earlier they would have found their error. Or not.
Anyways, Franklin's first guess was wrong and its the other way to his first guess. But who cares, so long as I get a good charge out of my iPhone batteries.:rockon: