inadiqate bonding from the consumer

[buzzlightyear]

been to price up a job, customer just has just moved in, the requirement was a couple replacement of lights ,new security light.
I asked the customer that I need to see the c/u and check the main earth bonding.
looking at c/u the main bonding to the MET .wait for it was two 6mm earths
from the c/u to the MET . water & gas 10mm. flipped the lid down on the c/u and to see what the MCBs are on any RCDs not one.
the customer says the place was rewired in 2006 .any paper work for that ,at the solicitors the customer says .
I then told the customer you need to speak to your solicitor .
I was then told by the customer I have property's rented out and have c/u like that .like victor melldrew I don't believe it.
having spoken about the security light going out side the back door
the customer said I will get that of flebay only about £20 quid
you will fit it she said .I will fit it but their is no warrantee on you supplying me with that .customer saying warrantee from flebay .
f77king customers what do they know.
rant over

 

[Octopus]

2 x 6mm earths is ok on a TNS...

 

[buzzlightyear]

no, TNCS , Murdoch. why bother with the earths .under parr
has they say .25mm tails .

 

[buzzlightyear]

what can you tell the dumb A** customers .

 

[Octopus]

I just walk away from such muppets .............lifes too short to bother with these types ..

 

[buzzlightyear]

I have Murdoch , some time I wished I become a plumber .
less grief.

 

[Pete999]

no, TNCS , Murdoch. why bother with the earths .under parr
as they say .25mm tails .

 

[Ian1981]

I’m confused, is the protective bonding in 10mm and the earthing conductor is 2x 6mm cables in parallel?
Plus is the MET not the earth bar inside the consumer unit?

 

[Pete999]

2 x 6mm earths is ok on a TNS...

Do you mean 2x6mm bonds?

 

[buzzlightyear]

I’m confused, is the protective bonding in 10mm and the earthing conductor is 2x 6mm cables in parallel?

yes Ian, 6mm from the c/u , did not open the c/u ,10mm from the ADS to the gas &water .but I could not confirm that they were done .sorry about that.

 

[Spunkywads26]

Feel your pain Buzz. I went to house to look at moving 2 sockets as a recommendation. Straight forward job, so did a quick Zs on the existing sockets and got 14Ω Then after checking all the terminations on the sockets on the ring and did it again and got 1.9Ω.

Went to CU and opened it up what a mess!!! Did a Ze test and got 1.9Ω on the TN-S. The customer then piped up and said 'Oh we had a problem a couple of years ago with something in here. Our previous electrician did some work to some other sockets and then when he tested the board he was having problems. He made a phone call and some guys came out and messed around with something and said I didn't have to have my drive dug up and that it is all ok'. I asked if there was any paperwork relating to this previous work and they said no.

I'm now waiting for western power to sort it out. I expect to see a new electrode in place. Wasted an hour of my life for no reward.

Oh, the main earth was 16mm and the gas and water were 16mm also......

 

[uksrevivor]

I’m confused, is the protective bonding in 10mm and the earthing conductor is 2x 6mm cables in parallel?
Plus is the MET not the earth bar inside the consumer unit?

I was always taught that the MET was the metal connector block outside of the consumer unit which has the DNOs incoming earth connected to it. Gas and water bonding is connected to this also and an earth cable is run into the consumer unit from this block. We dont place a Main Earth Terminal do not disconnect sticker inside a consumer unit.

 

[Deleted member 9648]

I was always taught that the MET was the metal connector block outside of the consumer unit which has the DNOs incoming earth connected to it. We dont place a Main Earth Terminal do not disconnect sticker inside a consumer unit.

It can be either a standalone terminal or inside a DB, see the definition of an MET in 7671. A label is only required if the MET is separate from main switchgear

 

[uksrevivor]

Nice 1 wirepuller i learn something every time i come on this forum but have personally never come across anything other than an external MET.

 

[westward10]

Only requires a notice if not within an enclosure not necessarily a DB.

 

[uksrevivor]

Only requires a notice if not within an enclosure not necessarily a DB.

Agreed i only place them on if the terminal block is visible and normally fixed to the crappy chipboard the DNOs use to fix there services to.

 

[Ian1981]

I would say that the block externally is the DNO source of earthing as is often the case with TNCS supplies,and that the MET is the earth bar inside the consumer unit in which your protective conductors and earthing conductor connect to.
Often larger commercial installations will have an external MET where everything connects to other than your circuit cpc’s.
If it was TN-S with an earth connection onto the sheath ,you wouldn’t connect your main protective conductors to the sheath of the incoming supply say Or mess about fitting an earth block.
Obviously if this is the case you don’t label it inside a consumer unit.

 

[uksrevivor]

Ok i might be opening up a can of worms here lol but i have only come across a DNOs incoming earth connected into a metal earth block that is attached to the wooden board in all earthing arrangements on domestic premises TT excluded for the minute.
In both TNCS/PME and TN-S the DNOs earth is connected into the external MET block. I class external as not in the consumer unit and not enclosed so it is visible. Bonding cables are connected into the MET and i have never connected gas/water bonding cables inside a consumer unit. Even in my books it is called main earth terminal and is the connection point for all our other earth connections.

 

[buzzlightyear]

it depends on how you bond to the water services& gas .
some times you could use the earth terminals in the c/u
or use the metal earth terminal on the board to the gas /water services by looking on pages 17&18pages on the osg .

 

[Ian1981]

Ok i might be opening up a can of worms here lol but i have only come across a DNOs incoming earth connected into a metal earth block that is attached to the wooden board in all earthing arrangements on domestic premises TT excluded for the minute.
In both TNCS/PME and TN-S the DNOs earth is connected into the external MET block. I class external as not in the consumer unit and not enclosed so it is visible. Bonding cables are connected into the MET and i have never connected gas/water bonding cables inside a consumer unit. Even in my books it is called main earth terminal and is the connection point for all our other earth connections.

My example would be take a new build installation TN-CS.
Meter and cut out is in an external meter box.
DB is internal 3 meters away say in the garage.
Where would you connect your main protective bonding conductors?
Bear in mind there’s no external earth block fixed to a wooden board the source of earthing is part of the cut out and the terminals are accessible with a hex key only.