Bonding to gas and water block of flats

[Electroglow]

Hello all,

Now a quick question for you all.

Incoming gas and water supply at the bottom of the property. No bonding is in place ATM.

Now I always take the earth from the cu to each meter for each flat.

If its the same single phase supply feeding the flats then on the incoming earth block can't we just bond each gas and water meter from there?

Saving the mess of chasing ect??

What's the thoughts

 

[Evans Electric]

As far as I know each flat has it's own bonding .

 

[matt.leung]

each flat needs its own bonding

 

[Electroglow]

But it's all the same connection All joined to the same point ! Il try and draw it to explain

 

[Evans Electric]

I know what you mean Electroglow but each flat has it's own bonding .

Imagine the metallic riser replaced with PVC but the flats remain with copper , there would be no bonding within each flat.

 

[Andy™]

Imagine the metallic riser replaced with PVC but the flats remain with copper , there would be no bonding within each flat.

replace the incoming with plastic, then it wont be extraneous, and it wont need bonded...

 

[Electroglow]

Ok... But then regs say bonding is required within 600mm of services. So if 10mm is ran from the flat to there meter then please tell me what's is the diff?

Unless its bonded at the incoming into the flat

 

[SLIPSHOD & SLAPDASH]

Are you saying there is only one supply company meter for all the flats in this block ?

 

[Electroglow]

No this is just a question is was thinking of today.

---------- Post Auto-Merged at 21:30 ---------- Previous post was made at 21:27 ----------

So what every one is saying each cu in each flat should be ran to the incoming service. Even if the 3 phase was in place only one earth block is provided any way so it's still connected to the same thing lol

 

[SLIPSHOD & SLAPDASH]

No this is just a question is was thinking of today.---------- Post Auto-Merged at 21:30 ---------- Previous post was made at 21:27 ----------

So what every one is saying each cu in each flat should be ran to the incoming service. Even if the 3 phase was in place only one earth block is provided any way so it's still connected to the same thing lol

I havent got the faintest idea what any of that means. Your OP said single phase, now you say 3.

How many flats are there ?

How many phases ?

How many meters in the whole block ?

 

[Electroglow]

Huh? This is not a real question. I am only asking your thoughts

 

[Andy™]

each should have their own bonding. not really much different to a row of houses, each has the same services and from the same transformer

 

[SLIPSHOD & SLAPDASH]

Huh? This is not a real question. I am only asking your thoughts

Ok, not how i read it.

If each flat has its own supply company meter then each flat need its own bonding. This does not matter whether the meter is within the flat or all of them are in a common area. If there is only one supply meter to the property and the landlord has fitted his own meters to each flat it could be argued bonding is only needed once at the intake positions.

Many sparkies miss bonding metallic waste pipes. Some old cast ones had rope seals that insulated sections and are not extraneous. Last week i carried out a EICR and all the waste pipes were welded lead.

 

[Electroglow]

Sorry mate I I didn't know that is what u ment by meter lol. Yes that's my point if there is one supply with one meter dno (supplied)and then was split in to say 4 flats then the only thing to bond is the incoming water and gas not from each cu..

I didn't mean multable dno meters

 

[Evans Electric]

I still think each flat has it's own bonding , if theres a CU in the flat and a water pipe enters the flat you 'd need to bond it where it enters the flat if poss.

As far as I know bonding is only ommitted when the services are PVC throughout .

 

[Andy™]

As far as I know bonding is only ommitted when the services are PVC throughout .

you can have as much copper inside as you want and not bond any of it, providing none of the incoming services are extraneous.

 

[steptoe]

within 600mm of where it enters the property,

read that as you will, for blocks of flats I class each flat as a property if it has its own CU.

 

[shed69]

I still think each flat has it's own bonding , if theres a CU in the flat and a water pipe enters the flat you 'd need to bond it where it enters the flat if poss. As far as I know bonding is only ommitted when the services are PVC throughout .

and, evans, my old friend, if the reading where it is copper after the alcathene is above 24000ohms or something around that value...... which ive yet to come across.....

 

[ADS]

within 600mm of where it enters the property,read that as you will, for blocks of flats I class each flat as a property if it has its own CU.

To expand on what Steptoe is saying, it really is quite simple:-

Each flat has it's own supply, regardless of whether it's a DNO supply or a 'landlord' supply via submains off the main board.

Therefore, each flat has it's own 'equipotential zone'.

Any metal pipework entering the flat will be 'extraneous', and therefore would be 'bonded' from where it enters the flat......to the MET of the CU inside that flat........or in the case of submains feeding each flat, it would be bonded to the EMT of the flat CU.

Extraneous doesn't just mean 'main incomming gas and water supplies', you need to read the definition again:-

Extraneous Conductive Part - A conductive part liable to introduce a potential, generally earth potential, and not forming part of the electrical installation.

Although the incomming services are unlikely to introduce earth potential to each flat, as they will be bonded where they initially enter the building, they could still introduce a 'potential' from one flat to another and therefore require 'bonding' locally.

It does say "generally earth potential" - not 'only earth potential'.

 

[SLIPSHOD & SLAPDASH]

within 600mm of where it enters the property,read that as you will, for blocks of flats I class each flat as a property if it has its own CU.

But if there is only one building supply & one DNO meter then it doesnt matter how many C/U there are .