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).

 

[Strima]

Those tails will need to be dug out and replaced. They will also need either RCD protection at the meter side or mechanical protection to prevent this from happening again.

Ideally the tails should be routed to negate the need for an RCD. It's going to cost him a few quid...

Send him this link: https://lmgtfy.com/?q=safe+zones+for+cables

 

[Dobes_88]

There should be RCD protection on those tails as they're buried <50mm without mechanical protection.

The only way unfortunately would be to dig it out to inspect further and potentially replace...

Looking at it the left hand side earth cable (looks like a 10mm from picture) could be connected to the gas or water pipes, arcing could potentially bring the pipes up to 240v - would advise to get someone out to at least have a closer look.

 

[ferg]

I might go as far as suggesting getting someone out to that tonight.

You wouldn't want that sitting around being live and it may not take much for the fault to start arcing.

 

[Ricard]

How long ago would regs requiring RCD or physical protection have come into force.

 

[Deleted member 9648]

You should not permit anyone to install an RCD on the supply side of the tails, it is likely your son will be plagued by nuisance tripping with total loss of power each time. This is would be a departure from Bs7671.The best option is to run new tails and earthing conductors in surface trunking which will remove the need for RCD protection on the supply side.

 

[Deleted account]

How long ago would regs requiring RCD or physical protection have come into force.

Hopefully some one will come along and confirm or correct this, but I think it was the 2013 reg changes or was it the 2011 to have cables buried 50 mm deep or have additional protection.

Sorry I was absolutely no help whatsoever ever there.

 

[James]

I would get someone out to replace the tails, however I am disappointed to see no capping over the cables to protect them from the plaster.

 

[GBDamo]

Be nice to see the damage in relation to the consumer unit.

Are they directly below? Is there any mechanical protection.

If not id be trying my hand at claiming its not correctly installed and look to dodge the bill.

Oh and pass on my congratulations, damn fine shot that.

 

[James]

Be nice to see the damage in relation to the consumer unit.

Are they directly below? Is there any mechanical protection.

If not id be trying my hand at claiming its not correctly installed and look to dodge the bill.

Oh and pass on my congratulations, damn fine shot that.

2mm to the right and you would have a live coat hook installed for the mother in law!!!

 

[Dustydazzler]

2mm to the right and you would have a live coat hook installed for the mother in law!!!

Let’s hope it was a wooden hook otherwise someone could have got a serious shock

 

[DPG]

however I am disappointed to see no capping over the cables to protect them from the plaster.

Pretty insignificant compared to the fact that there are live tails directly under the plaster with no protection though!

 

[Ricard]

Be nice to see the damage in relation to the consumer unit.

Hmmm, considering my son is an engineering graduate, it does look rather like he was trying for a Darwin Award.

Is there any mechanical protection.

If not id be trying my hand at claiming its not correctly installed and look to dodge the bill.

It looks clear to me there is no mechanical protection.

The building is probably 1960s or 70s I don't know when the electrical instalation dates from. But if there should have been mechanical protection then that might help reduce his bill.

 

[GBDamo]

Not much wiggle room there to ne honest, other than mechanical protection, the cables are where you'd expect them to be.

Might be worth confiscating his DIY toys until he can prove hes not suicidal

 

[ferg]

I have to agree with GBDamo those cables are exactly where you would expect cables to be.

It should also be said he's a very lucky boy.

 

[davesparks]

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

Looking at the likely age of the installation I woukd say its likely that it was permitted for those cables to be buried like that with no further protection according to the regulations at the time.

However the current regulations do not permit this so the replacement cables will need to have mechanical protection installed. Whoever carries out the replacement will have to work to the current regulations so will need to Chad eout the wall to install the protection.

So there will be an electricians bill to replace the cables plus the bill for a decorator to fix the wall afterwards, possibly plus a plasterer too depending on how bad the damage is.
You may be able to reduce the cost by offering to do the making good yourself if your DIY skills are good in that area.

 

[Ricard]

Thank you all for your replies.

Davesparks, that sounds pretty much what I expected. I guess wirepuller's suggestion re: trunking would be OK and cheaper but the landlord might not like it.

At least I have always found plastering is pretty easy as long as the area is narrower than a steel float, so hopefully the sparky will be tidy.

Will an electrician be able to do all the electrical work, or will they need to get the supply company in to connect to the meter?

 

[GeorgeCooke]

The supply company will need to replace the seals on the meter.

As it is a rented flat was he even allowed to drill holes in the wall anywhere? I guess the landlord is not going to be happy.

 

[Ricard]

As it is a rented flat was he even allowed to drill holes in the wall anywhere? I guess the landlord is not going to be happy.

The flat had been redecorated prior to occupation and was devoid of fittings like curtain tracks. The landlord had said it was OK to put up such things and until now there had been no problems.

I have always thought that an experienced person is just someone who has already made their mistakes. On that basis I expect that after this whopper, my son is unlikely to ever drill through a cable again. I'm just glad that this educational event only resulted in damage to the building.

 

[Lister1987]

On that basis I expect that after this whopper, my son is unlikely to ever drill again.

FTFY