3rd Amendment Metal Consumer Units - best practice advice please

[The General]

Afternoon all,

I've been doing domestic electrics for about 4yrs now and although I've done a few circuit alterations on metal clad consumer units I'd say that 95% of my work has been with plastic ones. I'm totally comfortable with replacing a consumer unit and all that it entails, but I've not done any commercial or industrial work - so I've had very little exposure to the actual 'physical experience' of working with metal boxes.

I'm hoping that those more experienced than me may be able to offer some help/advice on working with a metal clad box.

For instance, are there any handy little tools which I'm going to need to buy which will make life easier?
Are there any pearls of wisdom you can offer which might save me from a lot of cursing and swearing!??

I know that often, experience can only be gained by actually doing it, but I'm hoping that I might be able to learn from good examples before I end up making too many mistakes.

Thanks in advance for your input,

 

[Midwest]

Last metal CU I installed, I had to install surface. So I used plastic trunking (with lid & end caps), bushes & lockrings. That's pretty well 'sealed' & used 'good workmanship (I'd like to think!) & proper materials'. So I've complied with Guidance note 4.

 

[Midwest]

@ Elex, Sandown Park in 2014 stated that all these special cables entries were required!

AND he didn't like it when I asked why the schemes hadn't suggested a mains powered smoke in the same room as a sensible alternative!

They changed their minds at Harrogate 2015

https://www.youtube.com/watch?v=nJvLT7uwO58&feature=youtu.be

At 13.20 cable entry is discussed. Bottom line is maintaining IP ratings for cable entry, intumescent seals are NOT required, but if you feel like spending more money you can. Incidentally, Tel did you ask a question at 24.34 about tunnel terminals

 

[Barry White]

not the dno kit though and i bet that was what is causing a lot of fires in london, afterall its that overloaded and it should have been improved/replaced decades ago

I blame the Chaps who change the meters they often have to pull and twist the tails to do this and sometimes loosen them in the consumer unit or henly blocks (not on purpose of course) the only test they do is a polarity test (plugged a socket tester in nearest socket) and why has it been higlighted in recent years??? The smart meter roll out . Never have as many meters been disturbed at once and hence the fires.
Just my twopeneth.

 

[grumpyjohn01]

It has been suggested to me by those who reckon to know, that the area that originally yielded the stats for increased number of fires is one known to have a lot of overcrowded housing & hence overloading of CU's? If my experience of West London is anything to go by there are whole areas where at least 2 dwellings share each supply ( google beds in sheds). Just my tuppence.

 

[shanky887614]

It has been suggested to me by those who reckon to know, that the area that originally yielded the stats for increased number of fires is one known to have a lot of overcrowded housing & hence overloading of CU's? If my experience of West London is anything to go by there are whole areas where at least 2 dwellings share each supply ( google beds in sheds). Just my tuppence.

a lot of older houses are wired like that.

every other house gets a feed from the street and then its looped to another property before the meter

 

[grumpyjohn01]

a lot of older houses are wired like that.

every other house gets a feed from the street and then its looped to another property before the meter

well I'm sure the good old DNO has calculated that one out fully....! I was more meaning those areas where each house has an additional 'house' at the bottom of the garden accommodating another whole family in some cases. The whole lot being fed in some cases from a single CU in the main house via sub or whatever. My experience of this is in Hounslow but judging by the general cost of housing in the capital I'm sure overcrowding is inevitable everywhere and this sort of thing must happen a lot.