DIY Very Big Bang

[Ricard]

I am not a professional electrician and am posting this partly for your general amusement and partly to get some background advice.

My son who has recently moved into a rented flat in Nottingham having got his first job there, decided to put up some coat hooks. He seems to have taken insufficient notice of the fact that the consumer unit is above where he was drilling. Apparently there was a very big bang and the hole shown in the picture appeared without any further exploration on his part.

He phoned me for advice and sent me the pictures, mentioning that none of the fuses seemed to have blown and everything is still working. I explained that the reason no breakers had tripped was that these are the main cables coming into his consumer unit and therefore before his breakers. I am a bit surprised that the company fuse didn't blow, but I guess it must have been a very short bang.

My advice was call your landlord's agent, you need an electrician because there is no way you should attempt to do anything with this.

The consumer unit is near the ceiling on the opposite side of the wall to the meter cupboard.

My questions are first will there be any way to fix this other than digging out the cables and replacing them from the meter to the consumer unit.

Secondly to ward against the agent inflating the cost, what sort of ball park cost should it be.

Finally, is it appropriate for the main cables to be buried in the wall without any protection (from idiots).

 

[Lister1987]

Actually it is more likely to be a lagacy thing than any desire to make money, I'm sure if the whole cutout and meter arrangement was to be designed from scratch today it would be quite different. But it has evolved from the old ISCO and similar cast iron equipment.

It is not the damage done to the network which is the issue with 'yanking' the DNO fuse, it is the serious risk of injury to the person doing it or the long term fire risk if they don't carry it out properly.
If the load is not isolated when the fuse is pulled there will be arcing of the contacts which will leave them permanently damaged potentially creating a high resistance connection which could lead to fire further down the line.
Unseen damage to the fuse carrier or cutout could lead to it falling apart when pulled and leaving live parts exposed or causing a fault at the full fault current of the service, this could cause some nasty burns and blindness for the person doing it.

Which only furthers the question where there was/is not HSE/EWAR pressure for them to be retrofitted nationwide (what ais the DNO version of 18th Edition etc?) - DNOs of course will argue the seals are the 'safer' and 'more cost effective' method of protection

 

[Bobster]

It's always seemed funny to me the worry around pulling a DNO fuse.

As an apprentice I never batted an eyelid at pulling fuses from the bill/red spot boards. I still don't. They were quite often under load, with no way of isolating before hand.

If I ever had to pull a DNO fuse I'd just follow the same method, check it is in decent condition reduce the load as much as possible (it's domestic work so effectively you should always be able to reduce it to 0) and pull away.

Respect it, but don't fear it, that's when you make mistakes.

 

[Wilko]

Hi - if it makes you feel any better, Your Boy is not the first to do this. I’m glad he wasn’t injured.

 

[Wilko]

Secondly to ward against the agent inflating the cost, what sort of ball park cost should it be.

Hi - maybe £30 tails, £30 steel work and a day of work to dig out, remove and replace, add steel protection, replaster etc. Painting is another step at another time perhaps. Cost will vary, dependant on the length of tails, the final solution required, ease of access, other services etc. Nothing stopping Your Boy getting his own quote.

 

[Dustydazzler]

Qualified electrician is about £400 per day , electrical materials probably £50-£60 tops + a bag of plasterers bonding

So no more than £500 tops imo

 

[Dustydazzler]

An easier option would be to disconnect the old tails and just patch up the hole. Then use plastic trunking screwed to a made good wall then just pop new tails in the trunking.
This could probably be achieved in about 2 hours

 

[Spoon]

An easier option would be to disconnect the old tails and just patch up the hole. Then use plastic trunking screwed to a made good wall then just pop new tails in the trunking.
This could probably be achieved in about 2 hours

All depends on if the landlord would be happy with that?

 

[telectrix]

A good wrap of gaffer tape. 50P. black for the live conductor, green/yellow for the earth.

 

[ruston]

Or cut the cable lol and put an isolator switch as the join .

 

[telectrix]

Or cut the cable lol and put an isolator switch as the join .

now that is a cunning plan worthy of Baldrick. your prize is a giant turnip.

( and it's a lot cheaper than replacing the tails and replastering etc.,etc.)

 

[Dustydazzler]

Or cut the cable lol and put an isolator switch as the join .

Probably not enough slack on the wire in this case (by the look of the pictures) , but if there was some slack would be a half decent quick fix...

 

[ruston]

Probably not enough slack on the wire in this case (by the look of the pictures) , but if there was some slack would be a half decent quick fix...

Extend the tails from the top of the switch lol.

 

[Dustydazzler]

Extend the tails from the top of the switch lol.

But if your going to replace the top portion you might as well rip the lot out and start again

If the original tails were in capping not just plastered straight over the top you might have just about been able to pull a few inches of slack and adopted the isolation switch repair

 

[ruston]

@Dustydazzler . It was just tongue in cheek Dusty , but depends what kind of upheaval is involved for an economical solution. It's up to the landlord really , putting it back the way it was is just inviting another incident.

 

[Dustydazzler]

@Dustydazzler . It was just tongue in cheek Dusty , but depends what kind of upheaval is involved for an economical solution. It's up to the landlord really , putting it back the way it was is just inviting another incident.

I got the humour part but in jest it could have actually Been a fairly quick and cost effective solution