Question about main equipotential bonding

[jossper]

Hello - new member
I have a question about best practice regarding main earthing & bonding.Supply is TN-S 60 amp, MET block provided by DNO from braid off lead sheathed supply cables.
Nothing is curently connected to this MET block
Main system earth seems to be an uninsulated <6mm2 cable taken to incoming water main (lead pipe}
Obviously this needs to be upgraded. I will connect 10mm2 cable from CU earth bar to MET, bond Gas pipe to MET.
My question relates to the bonding to the water. The pipe comes into the building at the front of the house & runs under the suspended floor to the back of the house passing under the MET , sprouts through the floor at the back of the house where the main stopcock is. My qusestion is: where to connect the bonding?
1 at the front of the house where the pipe first appears under the floor (not easily accesible for inspection etc) - 8metre cable run
2 under the floor it passes under the MET - shortest cable ( 1.5 m) but not easily accessible
3 at the stopcock at the rear of the house (accessible) - 7 metre run

Also is this work notifiable to LABC as I am changing the main system earth?

Thanks
Paul

 

[RF Lighting]

IMO you should bond the water at the stop tap as per option three.


I don't think that what you propose will be notifiable, but I would wait for a second on just to confirm this

 

[DESL]

I'm a little confused with your description of main earth

Any chance of a picture of the set up so we can give you a more informed answer.

EDIT 1 : Upgrading of Main Eq Pot bonding is not notifiable

 

[jossper]

I think I'm peering into a can of worms here I have just had another look and the only earth I can find is a bare wire connected to water main and tee'd into the CPC of the ground floor ring in a junction box. I can't see any seperate earth from the CU & there is nothing connected to the MET. I will look again tomorrow & get the cover off the CU in the daylight. I'll try & post some pics - I know you all like them!

Thanks for your help.
Paul

 

[jossper]

OK, sorry for the delay, 'er indoors has been hogging the pc looking for shoes. As you can imagine this has taken some time! Here are some pics
Meter, cutout & MET, note nothing connected to MET:

This is the earth bar in the CU - no main earth, only CPCs:

This is a JB on the ground floor ring:

Uninsulated earth from above pic ends up here - clamped to lead water main:

Nice eh?
CU & RFCs were installed by an "electrician" about 1965
Was this ever within regs as an earthing arrangement?

Paul

 

[Steve]

Budget for a total rewire. Now.

 

[rjb]

Older installations use a gas or water metal service pipe as a means of earthing which is NOT permitted.

It has never been permitted to use a gas pipe and since 1966 it has never been permitted to use any other service outlet.

Every electrical installation requires a proper means of earthing normally via the distributor's earthing terminal (which you pictured with no connection to installation )

Sorry mate. Your whole system needs a complete upgrade.

There may be even loads of other faults. Even for instance if your cables were made between 1965 & 1971 they could give off a green goo caused by the amount of plastizier used during manufacturing reacting with the copper conductors.

 

[jossper]

Steve - I have budgeted for a total rewire - most wiring has already been replaced to a good standard - this is the oldest & worst part. My original question was about main bonding & earthing as a preliminary to changing the CU and rewiring all this. It was obvious the earthing was unacceptable so I wanted to sort it out immediately. I was asked for pictures - so I posted them - mostly for the amusement of the members of this forum.

Paul

 

[rjb]

Looking at your pictues the installation looks dangerous. I don't think anybody is laughing at them. I can assure you that members who frequently post and answer take electrical safety very seriously. Electricians and competent DIY'ers who help others here do it for nothing part from the gratification they are passing on information gained from years of experience. For comedy I turn into UK Gold or get out my Office DVD's rather than chuckling at uploaded shots of old CU's.

 

[JohnD]

well, it won't take you long to add improved bonding. You can put some 16mm G&Y into that MET and the earth bar in your CU (you will find the end hole is the biggest, but you may need to divide the strands into two prongs of a fork and use two holes). you can easily run some 10mm G&Y to your incoming gas and water services.

Buy some G&Y sheathing and put it round any bare earths you come across, but if you are planning a rewire soon, probably not worth going round every switch to do it.

This is easy DIY work, and not notifiable. You might get a bit dusty though.

 

[jossper]

A bit of background. I was an electronics engineer for 27 years & my employers were serious about electrical safety so I have received some training in this & understand about the significance of proper earthing and phase earth loop impedances and protective devices. I am not an electrician & I am not fully conversant with all the regs - in other words I know enough to know when I dont know something & I go and look it up or ask on a forum lke this. Hence my question about the bonding to water pipe

I recently inherited this house from my parents, so I have some knowledge of it's history. I was always pestering them to get the place rewired but they didn't want the disruption. As my father redecorated rooms I replaced the wiring in that room to current standards so most of the wiring has been replaced within the last 10 years All that is left is the parts of the lighting & rfcs in the hallway which includes the cabling to the CU. I was planning to replace all this shortly. Whilst looking at this I noticed the toytown earthing & wanted to sort it out immediately. The pictures of the existing arrangement I posted because:
1) I was asked to
2) as a warning to others
I didn't mean amusement in terms of ho-ho-ho - bad choice of words - my fault.
Thanks fo your replies guys

Paul

 

[jossper]

Any more opinions on my original question?

Hello - new member
My question relates to the bonding to the water. The pipe comes into the building at the front of the house & runs under the suspended floor to the back of the house passing under the MET , sprouts through the floor at the back of the house where the main stopcock is. My qusestion is: where to connect the bonding?
1 at the front of the house where the pipe first appears under the floor (not easily accesible for inspection etc) - 8metre cable run
2 under the floor it passes under the MET - shortest cable ( 1.5 m) but not easily accessible
3 at the stopcock at the rear of the house (accessible) - 7 metre run

Also is this work notifiable to LABC as I am changing the main system earth?

Thanks
Paul

 

[JohnD]

is this work notifiable to LABC as I am changing the main system earth?

no

 

[saxondale]

is this work notifiable to LABC as I am changing the main system earth?

no

will be when you get round to the new C/U though