Changing consumer unit in flat

[westward10]

Eh?

 

[bigspark17]

Just wondering if you carried out Ze, best do that 1st and take it from there.
I think you will find it will be within limits.

Ive seen loads of 6mm earths and tested fine and no you can not TT, if you have an issue with the earthing you ring dno.

Good luck

Double ehh????

 

[DPG]

Triple eh???

 

[Sparkie30]

Double ehh????

Really ??? Where??

Cant see where im repeating you, do apologise if that has offended you and others.

Thank yu

 

[bigspark17]

Really ??? Where??

Cant see where im repeating you, do apologise if that has offended you and others.

Thank yu

Hi @Sparkie30 you havent offended anyone but your reply made little sense to the OP predicament..
1-how is checking ze going to help with his bonding predicament
2- the op hasnt questioned any ze max values
3- yes you can TT without contacting DNO

 

[Ian1981]

If the main earthing conductor is 6mm and has been in place for quite a few number of years and shows no signs of thermal damage it maybe adequate
By carrying out the aidiabatic equation it maybe an adequate CSA and can be left and a note made on the certificate

 

[DPG]

If the main earthing conductor is 6mm and has been in place for quite a few number of years and shows no signs of thermal damage it maybe adequate
By carrying out the aidiabatic equation it maybe an adequate CSA and can be left and a note made on the certificate

But the bonding issue?

 

[Dave OCD]

And earth fault current will always be limited by the 60a sub main fuse.

 

[westward10]

If the main earthing conductor is 6mm and has been in place for quite a few number of years and shows no signs of thermal damage it maybe adequate
By carrying out the aidiabatic equation it maybe an adequate CSA and can be left and a note made on the certificate

It isn't the earthing conductor it is a cpc. The issue is its ability to support PME bonding.

 

[Sparkie30]

Hi @Sparkie30 you havent offended anyone but your reply made little sense to the OP predicament..
1-how is checking ze going to help with his bonding predicament
2- the op hasnt questioned any ze max values
3- yes you can TT without contacting DNO

1- Ive never said checking ze is going to help with his bonding
The op was asking about his earthing in his 1st post
2- the op has said its pme so i guess he knows max ze value
3- no you cant unless you get permission from local authority and survey the area, and im sure if you have a eathing issue ukpn or local authority will attend pretty quickly from my experince anyway.

 

[Ian1981]

From what I read it's 25mm incoming tails and a 6mm earth.
No mention of a sub main circuit

 

[Sparkie30]

It isn't the earthing conductor it is a cpc. The issue is its ability to support PME bonding.

Thousands and thousands of council flats in south london are on 6mm earth and 10mm bonding just saying

 

[westward10]

Am I dreaming all this.

 

[Toneyz]

Please confirm landlords cupboard with Ryfield board to meter -meter tails (what size) 60A switch fuse what cable between switch fuse and flat consumer unit ?.This is always going to be a problem when a installation is constructed to a previous addition of BS7671.

 

[Ian1981]

But the bonding issue?[/QUOTE

Am I dreaming all this.

is it a main BEMCO unit at origin with meter tails fed from DNO fuse to an isolator ?
Or just tails from the BEMCO straight to the flat?
Suppose either way upgrading bonding to 10mm is irrelevant if the earth/cpc is only 6mm

 

[bigspark17]

Im getting dizzy this thread is going round in circles!!! Op if u want pm me

 

[Sparkie30]

Im getting dizzy this thread is going round in circles!!! Op if u want pm me

Me too, im out. Bed time.

 

[Sparkie30]

This is what you find normaly.

View attachment 35662

View attachment 35661

 

[robo83]

I don't have anything like that. I've attached a picture of the DNO cupboard.

Ze at consumer unit 0.33

View attachment 35665

 

[Midwest]

Interesting conundrum, I haven't any answers just some questions for members.

Clearly not a unique situation. As regards the bonding of services, surely this is done at the intake position for all the flats, as this where the service pipe enterers the property (as a whole) and that is where the bond should be, not in each individual flat?

As the service enters each flat, it may then become an extraneous conductive part and may require bonding or reg 528.3.4 might also apply?

Why would consideration be given to converting to TT, when the property has a perfectly good earthing system (not with standing the bonding issue), and more than probably realistically unachievable?