Consumer Unit replacement

[user 27969]

Hello!

whilst my electrician was round, he made some criticisms of the main fuseboard / consumer unit in the flat. He told me that the main unit needs replacing with an RCD protected modern unit. He also said that my flat was the main entry for electrics into four flats, with two flats next door supplied through horizontal conduit metal, and one flat upstairs vertical conduit metal. He pointed out the degradation of the wire leading into this metal conduit and the danger.  I trust him but wanted opinions from the boards on the best way forward and possible cost implications.

 

[Rob_the_rich]

Why did he say your consumer unit "needed" replacing with a modern unit?

I cant really see degradation on the cables to other properties in that photograph, can you see bare metal?

Edit; also, it seems odd that the supplies to four flats are all fed from one phase and one meter (changed recently?), when there are two "spare" phases.

And the conduits supplying the other flats do not appear to be earthed.

And I see two live cables going next door but only one neutral

 

[user 27969]

Why did he say your consumer unit "needed" replacing with a modern unit

• i think it was to add RCD protection to the config.  
  
• I can't see bare metal, but i can see the outer cable protection looks pretty old and cracked. 
  
• he said the other flats were not on my meter...
  
• (the metre was upgraded from old style recently by edf or whoever usually does that)
  

Cheers Matt

 

[Essex1]

On the face of it it is completely reasonable to offer you a CU replacement.  You do not appear to have any RCD protection which is almost certainly required in a domestic setting.  

 

[Rob_the_rich]

yep, my bad, the other flats are not on your meter.

Does seem a bit radical to change a CU just to add RCD protection for a bathroom cabinet. Might be easier to find the lighting feed to the bathroom and put an RCD fused connection unit on it.

He needs to protect the bathroom cabinet, because he installed it, but there is no requirement to upgrade the CU. You do get the benefit when changing CU of RCD protection to whole flat.

I think the cables to the other flats belong to the DNO, it might be worth contacting them about their condition. I can see why you are concerned if that is the light switch to the cupboard just above.

Edit; So if the conduits aren't earthed, does that mean that the neutrals are PEN conductors? yet the installation seems to be TNS. Not asking you Matt, but others here may know.

 

[user 27969]

hello,

I don't think he was saying it directly in reference to the bathroom cabinet install, but general advice.  He said he'd done another similar flat in the area where the wire was showing.  

"You do get the benefit when changing CU of RCD protection to whole flat" this sounds like a good idea... 

i think the white wire / fuse box is to an old burglar alarm (decommissioned), so not used but probably needs ripping out (by a professional)

So the suggestion about DNO... turns out its 'UK Power Networks' if i take your meaning, so i might give them a call and see what they say.

thanks for all your input (s)

Cheers M

 

[user 27969]

phoned UK Power Networks, and i think they are going to come round and check it...

 

[Blue Duck]

bit of a mine field to sort this one out as UKPN will want everyone to have their own supply. 

lucky you have a 3 phase service head / cutout. well lucky for 3 people not so lucky for one person...

Anyway everyone has to agree to the works or it all falls to peices.

good luck  ray

 

[user 27969]

hopefully they will all agree if works needed..... or i just get all of them disconnected, apart from mine

 

[ProDave]

The best way to get the DNO's attention, is to report a "dangerous condition" Those look like old cotton covered cables, with cracks in them, and a seemingly un earthed metal conduit, so it is not unreasonable to think that might be dangerous.

When the guy comes to fix it, suggest to him that they should be re connected using all 3 phases to share the load. At the moment all 4 flats are fed from one 100A fuse. If you all take a shower at the same time (assuming you all have an electric shower) that fuse will likely blow.

Re your consumer unit. Are you a firsrt floor or ground floor flat? are you likely to use any outside equipment (if you have a garden)?  If so a good argument for upgrading the consumer unit.  Also if you plan on renting the flat out, you would be well advised to upgrade it as you have a duty of care to your tenant. But as already pointed out, nobody can force you to upgrade it if it is your own home, only advise that it might be a good idea. Assuming there are no faults, it is not normally a particularly expensive job.

I would be interested to know what the other flats do for an earth.......

 

[Andy™]

other flats are probably TT. seen many installs where one incoming supply is TN then next property looped similar to that as TT

 

[Rob_the_rich]

other flats are probably TT. seen many installs where one incoming supply is TN then next property looped similar to that as TT

don't see much TT in London, how would it work with an upstairs flat? Would they need to ask for permission from owner of downstairs flat to drive a spike in their property?

 

[binky]

that's old cabling alright, the DNO will possibly get a third party to repalce the runs.

As for RCDs, pefectly acceptable recommendation. I doubt your flat has been tested in decades, so it would be good to get it tested and updated, same as you would MOT your car.

 

[Andy™]

don't see much TT in London, how would it work with an upstairs flat? Would they need to ask for permission from owner of downstairs flat to drive a spike in their property?

generally upstairs flats have a small hallway downstairs where you can lift a board and fit a rod, failing that, they often have either a bit of front garden or back yard where one can be fitted

rarely ever have any problems trying to find somewhere to fit a rod up here. for a fairly built up area, there is a lot  or TT

 

[Rob_the_rich]

just having another look at the pics, cos I was a bit confused about it earlier, there is a new red cable coming out of one phase of the 3 phase head going to Matt's meter

Another red cable seems to come out from the side of the box to feed the other 3 flats. It does not seem to be fused. That can't be right can it?

 

[Andy™]

well spotted. it could be connected to one of the fuse holders from the bottom, but that doesnt make sense. so i guess there is a fuse in each property?

 

[Rob_the_rich]

I know the DNO don't work to BS7671 but to run an unfused supply through unearthed conduit seems dangerous to me.

Edit; found ESQCR 2002 reg 10 http://www.legislation.gov.uk/uksi/2002/2665/pdfs/uksi_20022665_en.pdf

"Earthing of metalwork

10.—(1) Subject to paragraph (2), and without prejudice to any other requirement as to

earthing, a generator, distributor or meter operator, as the case may be, shall ensure that any

metalwork enclosing, supporting or otherwise associated with his equipment in a network and

which is not intended to serve as a phase conductor is, where necessary to prevent danger,

connected with earth."

 

[binky]

it is, conduit should be earthed, but bond has no doubt been lost in the 'mists of time'

 

[user 27969]

each of the flats do have access to a ground-floor hallway, however, who knows if each flat has a proper earth. Im still waiting for DNO, but will re-post once they have looked at it.

thanks again for all the input, cheers Matt

 

[ProDave]

well spotted. it could be connected to one of the fuse holders from the bottom, but that doesnt make sense. so i guess there is a fuse in each property?

That's VERY dodgy if that feed to the other flats is not fused.

So three flats, each probably with a 100A fuse of their own, fed from one cable via a henley block.

Now remind me what's the rating of a single pole henley......