Hi

I wonder if anyone has any useful thoughts on this. Client wants me to redo consumer unit but doesn’t want disruption to fabric of building. I’ve attached pic - looks like original wiring was a 16mm earth to the live incomer .

The meter box is >20m away.
I guess cable is cable but 16mm would be undersized in a modern installation
I don’t understand why it was done like this since the house was built 2011 from ground up, so no retrofitting.
This is one of two consumer units, both of which have Knx units in same unit (which they shouldn’t) , and will be migrating them to a different system that will work better for the client.
The latter is relevant as it appears the KNX install was done by someone who had no idea, nor the software to programme it all, so none of it works as it should, but is now
67C65FFB-CDAE-4F0B-98DC-9A37E5AA2688.jpeg
 
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You sure the neutral isn’t blue tape over earth as well?

Badly crimped earth wire in the back and some phone wire?

16mm is fine IF it’s fused appropriately.
At 20m to meter, are these single tails? Protected in conduit or anything?
 
Thanks for prompt response

Neutral probably the same yes but can’t confirm yet
There’s a lot of other dodgy and messy wiring in there, but the rest would reasonably easy to resolve in the consumer unit

Im going back to property today to look at a bit more, as I wrongly assumed there would be no problem to the unit!
But if they are earth cables that have been taped, then that would mean they are single insulated, so would need to be in conduit or something.
Have no idea how I would run new meter tails if they don’t want any disruption to building fabric!
 
What is exiting the incomer meter/isolator/ (kmf?) Clearly, if you’ve proper tails one end and then this at the other then somewhere there’s a join - which personally I’d be more concerned over than the issue of non-compliance (lack of sheath) or questions about sizing.

I’m going to go on a limb of a guess of the back story, here…. There’s a KMF after the meter and proper tails won’t fit the termination, ‘electrician’ then realised that 16mm single wasn’t on the shelf at the wholesaler in anything other than G/Y unless they got a 100m drum in of each colour, special order.
 
What is exiting the incomer meter/isolator/ (kmf?) Clearly, if you’ve proper tails one end and then this at the other then somewhere there’s a join - which personally I’d be more concerned over than the issue of non-compliance (lack of sheath) or questions about sizing.

I’m going to go on a limb of a guess of the back story, here…. There’s a KMF after the meter and proper tails won’t fit the termination, ‘electrician’ then realised that 16mm single wasn’t on the shelf at the wholesaler in anything other than G/Y unless they got a 100m drum in of each colour, special order.
Yes, I’m guessing same, but will give update when get chance to go to property - which I won’t now until Monday as client not available until then
 
Thanks for prompt response

Neutral probably the same yes but can’t confirm yet
There’s a lot of other dodgy and messy wiring in there, but the rest would reasonably easy to resolve in the consumer unit

Im going back to property today to look at a bit more, as I wrongly assumed there would be no problem to the unit!
But if they are earth cables that have been taped, then that would mean they are single insulated, so would need to be in conduit or something.
Have no idea how I would run new meter tails if they don’t want any disruption to building fabric!

As said above probably the only cable they had was std g/y 6491x .

Which would be unsuitable, firstly because it is single insulated, (unless it's run in conduit or trunking over it's whole length); but also because it is prohibited to oversleave g/y as any other conductor.
 
As said above probably the only cable they had was std g/y 6491x .

Which would be unsuitable, firstly because it is single insulated, (unless it's run in conduit or trunking over it's whole length); but also because it is prohibited to oversleave g/y as any other conductor.
I was holding back from the G/Y ident issue until I’d dug out my 16th ed and double checked what we were allowed to do back in 2010! I’ve a sneaky feeling I remember the whole G/Y exclusivity was 17:1??
 
I am sure I remember not repurposing green yellow going back to the 16th.
 
Tbh, I was always taught never to over sleave g/y right back from the late '70s (not that we over sleeved much then anyway)

As you say I don't know when it became "official" but I expected it to be way back tbh.
 
OK made me check, but the red book of 2008 has reg 514.4.2 indicating g/y must only be used exclusively for cpc/earth bonding etc

It was also in regulations B54 and B57 of the 14th edition - although B57 was for all flexible conductors.

Although the earth could be solid green up to 1977 of course.

It also wasn't as specific back then, the regs were more "you understood and applied their meaning " rather then today where they have to spell things out somewhat more.
 
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Any practical solutions that don’t involve cutting new holes to run a new cable ?
Without actually seeing it ‘for real’ it’s hard to say but I’ve a suspicion that you may be on a loser with this one. Even if hypothetically each cable was totally unsupported/fixed and could be used as a draw for a replacement, the replacement will be physically larger so I’d wager a reasonable round of drinks that you’d never get the new through the old holes.
 
If I understand correctly, these existing runs of 6491X are not in conduit or trunking, so the colour and size are immaterial, they are not suitable. Any replacement is going to be sheathed and therefore larger. Is there in fact a switchfuse at the origin protecting them? You describe them as meter tails (i.e. not a protected distribution circuit) but they are over 20m long.

If they were in conduit, and protected against overcurrent by a switchfuse at the intake, then we are back to the questions of size and colour. Does the situation satisfy Ib<In<Iz? And, are the cables taped in the correct colours over their entire length? Because 514.4.2 refers to a conductor coloured G/Y throughout its length, which is not permitted to be oversleeved at the terminations. But a cable completely covered in brown tape isn't a cable coloured G/Y throughout its length, it's a brown cable, and it's not oversleeved at its terminations. But then again, is that colour coding durable enough - the tape might start peeling off - as it's not part of the official make-up of the cable to the BS. The regs don't actually define this situation, IMO. I wouldn't accept it,
 

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Live incomer is earth cable wrapped in brown tape?
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