Main Feed versus drill

[Lainey]

Morning all

So I drilled through the plasterboard wall, the main fuse box was on the other side. I've gone though the main feed to the house. The power stayed on following a bang and some sparks, melted my drill bit... I'm alive so that's a good start. 

The main feed was touching the plasterboard behind where I drilled, it was wrapped in plastic, no protective metal or gauze that I can see, just lots of wires wrapped in black wire. 

It's a new build, two years old. Shouldn't there have been some sort of protection? 

The electrician has stopped the supply to the house, I'd already knocked it off at the fuse box. 

 

[Sharpend]

What else did the electrician say and where was he from? A local spark or from supply company? 

 

[Lainey]

What else did the electrician say and where was he from? A local spark or from supply company? 

He said they'd need to replace the feed, so might have to take some parts of the internal walls down. Other than stopping the feed to the house, he didn't say much. It's a housing Association so I rang the emergency number, they sent out the electrician. 

 

[TonyMitchell]

In the meantime, leave the whole area, walls included, well alone.   The DNO will treat this as an emergency as it is potentially dangerous since the supply side may still be energised.

 

[Lainey]

In the meantime, leave the whole area, walls included, well alone.   The DNO will treat this as an emergency as it is potentially dangerous since the supply side may still be energised.

The electrician took the fuse out of the main outside meter box and put a lock on it. I dont think they'll be any power at all coming into the house. 

 

[Geoff1946]

Ah, if its downstream of the meter, it's not what is commonly referred to as "main feed", (although that may be a description of its function)

Main feed usually means the supply authority owned cable which stops before your meter.

Regarding your original question, about protection I think you may have a case to complain but there are others on here better versed than me in those rules.

 

[kerching]

If it's black it sounds to,me like it may be an armoured cable from the 'meter box' to the distribution board

just saying

 

[Doc Hudson]

just lots of wires wrapped in black wire. 

It's a new build, two years old. Shouldn't there have been some sort of protection? 

If it's black it sounds to,me like it may be an armoured cable from the 'meter box' to the distribution board

just saying

I am inclined to think this is probably an armoured cable, by the "lots of wires description"

Doc H.

 

[Lainey]

I am inclined to think this is probably an armoured cable, by the "lots of wires description"

Doc H.

I believe it should be an armoured cable but the electrician says that's half the problem, there wasnt any armour so I drilled straight through it

 

[Sidney]

Armoured cable won't stand up to a drill. Sounds like you had a very lucky escape.

Any chance of some pictures?

 

[Lainey]

Armoured cable won't stand up to a drill. Sounds like you had a very lucky escape.

Any chance of some pictures?

Will get some posted when its light again. I do feel fair lucky

 

[ProDave]

The lesson from this is look BOTH sides of a wall before drilling.

My guess would be a split con, but none uf us know for sure what cable it is.

If it's 2 years old then there should not be a buried cable that is not either RCD protected, or encased in steel conduit.  So if the HA try and charge you for the damage, point this out that it probably does not comply with the wiring regs.

 

[SPECIAL LOCATION]

I believe it should be an armoured cable but the electrician says that's half the problem, there wasnt any armour so I drilled straight through it

Any half decent drill can get through PVC, Wood, Plaster-Board, Metal (pipes or cable), Brick, Concrete, Mortar.....  etc..  etc....

The phrase "Armoured" as in Steel-Wired-Armoured" cable isn't exactly as strong as it may sound....

More intended to prevent a spade chopping it in half if buried in the garden...

But if you decide to drill it...

Well I am guessing a non-blunt drill bit could make sufficient impact to make a big bang!!!!!!!!!!!!!!

As has been said...

If this cable is after your suppliers meter it will be within the remit of BS7671...

And if it is buried in the wall...

Then RCD protection OR mechanical protection should be provided.

Guinness  

 

[Lainey]

 Pics..  small drill bit size hole to the cable. Should it be so close to the plasterboard wall? 

 

[Geoff1946]

Looks like wire armoured to me. As others say it's protected but not bomb , (or drill), proof!

 

[Lainey]

Looks like wire armoured to me. As others say it's protected but not bomb , (or drill), proof!

Thanks Geoff. Electrician says he could resight the fuse box in the downstairs loo to avoid internal walls coming down. Might even get the power back on today

 

[Lainey]

Any half decent drill can get through PVC, Wood, Plaster-Board, Metal (pipes or cable), Brick, Concrete, Mortar.....  etc..  etc....

The phrase "Armoured" as in Steel-Wired-Armoured" cable isn't exactly as strong as it may sound....

More intended to prevent a spade chopping it in half if buried in the garden...

But if you decide to drill it...

Well I am guessing a non-blunt drill bit could make sufficient impact to make a big bang!!!!!!!!!!!!!!

As has been said...

If this cable is after your suppliers meter it will be within the remit of BS7671...

And if it is buried in the wall...

Then RCD protection OR mechanical protection should be provided.

Guinness  

Electrician here. He said theres an RCD on the fuse box side but not where I was drilling. He said I've missed the neutral and the earth. Gone into the live 

 

[ProDave]

Electrician here. He said theres an RCD on the fuse box side but not where I was drilling. He said I've missed the neutral and the earth. Gone into the live 

That's not possible. the earth will be the outer steel wires.

 

[Sharpend]

It may be that the third core is used as earth, whether they’ve taken the time to earth link the armouring is questionable? Given there was a bang then I suspect they may have. 

 

[Evans Electric]

To my mind that install is well out of order ...an SWA  sub - main hidden against the back of a plasterboard wall  with no protection ... someone could drill right through it .

New build eh !   So all the other houses will be the same  no doubt .