No Bonding to my gas pipe - is it worth adding one ?

It's great working shifts :LOL:
It is a fundamental requirement of the IEE regs that the earthing and bonding should have been checked before any alterations or additions are carried out.
I take it he gave you the electrical installation certificate?

I hear what you are saying.

I also don't know why there are 2 earths from the CU to the MET, however I did used to have 2 x CU's before, a normal one and a seperate one for the economy 7 strorage heaters so the spark probably used both for the new single split load CU.

I work within 'very' strict rules and regs in the Commercial Aircraft maintenance industry. However like all things we do there has to be a certain amount of common sense applied, I've been doing my job for nearly 25 years now, my experience is worth more than any qualifications and authorisations that I posses, luckily I have plenty both though...
I very often have to Certify and over-sign jobs as an inspector that i haven't actually done myself, luckily i totally trust the guys who i work with. They often have to do the same for me...

My existing electrical installation seemed perfectly functional and i could have legally gone on using it for many more years to come. When i decided to get power out to the shed after years of wanting to do it i decided that the house electrics should be looked at more closely too, this is why i got the CU upgraded.


My spark seemed like a decent bloke, I have enough electrical experience through my own job to speak to him on the same level. I employed him via a boxed advert in the local yellow pages. I even offered to pay him cash on completion , but he was having non of it , insisting that he would issue my with an invoice, i could pay him via cheque and he would then issue an official company reciept , detailing work carried out., Quote: " To keep all of the papework striaght. i.e. He wasn't just a geezer i met down the pub who used to do a bit of sparking a few years ago :D

I did have the odd look to see what he was upto , just for my own interest more than anything else, nothing worse than somebody looking over your shoulder all the time when you are trying to get a job done. In fact i even gave him a hand to route some of the tails etc under the floors ( sparkies obviously don't like getting dusty :) ) You can be assured though that as soon as he was out of the door I had a much closer look at what had been done - I watch rogue traders on TV too :D .

I've made full use of my new toys , namely a Megger 320 RCD tester and LT7 Loop Tester. When i follow the instruction on the instruments user manual and also guidlines in my Amicus Pocket testing guides everything seems to check out OK, giving readings that seem to be well within acceptable limits. I've not done all of the High current Loop Tests though- need to do a bit more reading for that. The low current auto tests seem to be OK.

The bottom line is that i feel that my House electrical installation is now much more safer than it was early last week. My old re-wirable fuses have gone ( some of which were over rated - the old shower circuit was shockingly illegal & dangerous !) and I've got MCB protectin on all circuits and effective RCD protection on all of the ones that really need it ( all house, garden & shed socket outlets) - this can only be a good thing in my view.
Sure i have discovered a couple of minor things with the earthing and bonding that that require rectifying, however the important things is that they they 'have' been discovered and that they 'will' get rectified, and mostly thanks to the helpful and friendly advice i've been given on this discussion forum :D.

Best Regards
 
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Has your garden shed circuit got an RCD at the shed end of the circuit?
 
Has your garden shed circuit got an RCD at the shed end of the circuit?

Yes.

Garden shed is connected to the house using an 8m - 10m long , 3 x 6mm² core buried SWA cable. It is connected via a B32 MCB on the non RCD side of the House CU.
I have another 2 way CU in the shed fitted with an 30ma RCD/Isolator. Sockets are connected via 4mm² T&E protected by a B20 MCB, the 2 lights are connected using 2.5mm² T&E on a B06 MCB.
The Shed CU was a plastic one so i terminated the SWA into a metalclad box, then extended the insulated cores up into the CU.
All T&E has been re-routed inside plastic trunking, since this piccy was taken.
Volex%20CU.JPG
 
OK I've done a bit more grubbing around in the dust. I did fit the new Main Bonding cable to the Gas Pipe and also updated some of my other bonding connections, most of which where done by previous occupants and tradesmen i might add.
Quite a few of the cross bonding clamps in various locations about the house used seperate lengths of wire beweeen them , some of which had become a bit loose and (mildly) corroded in places. I've redone these with continuous cable 'loop through' method. for example here at my Combi Boiler:

I assume that by X bonding at the combi boiler inlet and outlet pipes 90% of the copper pipes in my house will be 'electrically' connected as I've not found any plastic supply pipes, just soldered copper, or brass compression joints.
My Water mains inlet is below the Kitchen sink and whoever fitted the Main 16mm earthing cable here also X bonded to the Kitchen sink hot & Cold Water taps using 10mm, this 10mm also went back to the old CU, I have slightly revised this arrangemnt.

The kitchen, Bathroom and Cupboard that house the Combi and CU's are in adjoining rooms with just 2 or 3 meters seperating them, this is why all of the bonding in these areas are then cross connected into a second earthing block, it was just easier to do it that way. Although i also used Crimped copper tube lugs bolted together with M6 nuts and bolts to make some of the connections.
Every connection has a metal warning notice attached.

The schematic diagram below is now a very reasonably accurate picture of what i now have in the house.

I've connected a continuity meter to my newly re-sited M.E.T pictured below my main CU below:
View media item 984
Using a (nulled) long test lead I wandered around the house checking exposed metal pipes, Metal units ( eg the Stainless Steel Cooker) and radiators etc, as well as a selection of Earth connectors at socket outlets and light fittings on all current 'in use' circuits. In all cases the readings where low, anywhere in the region of 0.00 Ohms to 0.10 ohms, obviously depending on the distance from the MET and the type of metal contact being checked. Mostly though the readings i got where about 0.05 Ohms.

Basically everyhting seems to be Cross connected to everything else so i believe i do have a genuine equi-potential Earth bonding in the house now.

Any obvious ommisions , or can i have a sit down now ;) [/img]
 
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The metal CU on the left hand side, the phase and neutral tails are entering via separate holes, should be through the same hole (to cancel out any electromagnetic effects.)
My opinion is you do not need to connect the boiler directly to the MET, nor the kitchen sink nor the supplementary bonding in the bathroom. Unless that is for some reason they are deemed to be extraneous conductive parts?
 
The metal CU on the left hand side, the phase and neutral tails are entering via separate holes, should be through the same hole (to cancel out any electromagnetic effects.)

Noted. This CU is totally dedicated to supplying power to my Hi-Fi System. I went for a seperate CU several years ago ( on advice) after suffering from mains noise. It turned out to be (several ! ) faulty control boards on my Worcester-Bosch combi boiler, i think they were destroying themselves due to certain relays arcing, it took 5 replacements to fix- luckily all under warranty.

I fitted this second CU myself, although it was (honestly) a direct replacement for a previous -non RCD unit that had been in place for a number of years. I will consider revising the routing, although I'm not getting any obvious adverse effects through the Hi-Fi- quite the opposite in fact :)

An Isolator at the meter and a local service block near the CU's make these things so much simpler....


My opinion is you do not need to connect the boiler directly to the MET, nor the kitchen sink nor the supplementary bonding in the bathroom. Unless that is for some reason they are deemed to be extraneous conductive parts?

Noted, i could easily disconnect these connections, but as they are already actually in place will it have any detrimental or even dangerous consequences if i leave them in place.
Some of these connections were already in place before i got to them, but i'm happy to ditch them if needed.


I've got several electrical books in the house at the moment*, plus other web based resources, all of them at least 16th Ed and all of them seem to have ever so slightly different pictures, diagrams and text regarding Earthing and bonding.
All really very similar mind, i basically tried to ensure the earthing & bonding that i had at least looked extremely similar to these. The actual main bonding conductors to the MET being my main concern though, hence the thread title :) .


* Books i refered to:

OSG ammd 1 & 2
Electric Wiring Domestic (scaddan, coker, turner)
Electrician's Guide to good Practice 2008 17th Ed - Amicus/Unite Union
Wiring & Lighting Manual - Readers Digest

Thanks for your help , much appreciated.
 
Have I got this correct?
The guy changed your consumer unit but let you with gas supply not main bonded?
Did he give you an Electrical Installation Certificate for the works?
Has he notified Local Authority Building Control? (you should receive this within 30 days of the work being done if he is registered or alternatively Building Control would have been around whilst work in progress if he is not registered).
Sounds like you might have some supplementary bonding that is a bit over the top but not determentral.
However those twisted connections are diabolical, they should have been soldered opr crimped if hidden or they may be screwed connections if accessable.
 
Have I got this correct?
The guy changed your consumer unit but let you with gas supply not main bonded?
Did he give you an Electrical Installation Certificate for the works?
Has he notified Local Authority Building Control? (you should receive this within 30 days of the work being done if he is registered or alternatively Building Control would have been around whilst work in progress if he is not registered).
Sounds like you might have some supplementary bonding that is a bit over the top but not determentral.
However those twisted connections are diabolical, they should have been soldered opr crimped if hidden or they may be screwed connections if accessable.

Hello ebee,

I've discussed this before so don't really wish to rake over the old coals again, but i did contact my local Building safety & Standards office ( as my Local Authority Building Controlis now calling itself up here in Scotland ) . I dicussed at length the scope of the work to be carried out on two seperate occasions and spoke to two differnt guys, both of them told me that i could go ahead and get the work done and they ( BS&SO) would not be interested in coming out to inspect this work, I was even told i could do it myslf if i wished to.
I know that the rules maybe a bit different down in England & Wales with Part P and all that but that my friend is the truth.

So anyway , I decided to employ a Sparky to do most of the work for me , in replacing the previous two CU's with the newer RCD split load.
He must have just used the Old earthing connectors, i know that he tested some stuff because i saw him doing it, maybe the readings were all looking OK ?? so didn't need to look any further :confused:

I had my Electrical installation upgraded and modernised because i wanted it done, not because it was faulty or causing me any specific problems. I just had the inclination and a little bit of spare time & cash to do it.
I could still be using the old installed CU's with their re-wirable fuses, I reckon that I am in a much safer envoironment right now...

I also work in a Highly regulated industry , (sometimes as a Licenced & Qualified Electrician even :) ;) ), however sometimes you just have to use a bit of common sense and if still not sure ask the relevant questions...

The actual main bonding cable from the gas main was left off by the guys who installed the gas central heating a few years ago. I employed a very well regraded local Corgi registered installation company ( now part of the Nationwide gas care Network - and not the cheapest quote either ! ) and not knowing anything about Gas central heating at the time just trusted that they would do the job properly, just goes to show what can happen if you blindly trust tradesmen just because they belong to an officially recognised scheme....

I have had some great advice over the last few weeks on this forum and appreciate folk taking the time to help.
 
The metal CU on the left hand side, the phase and neutral tails are entering via separate holes, should be through the same hole (to cancel out any electromagnetic effects.)

I didn't quite put them through the same hole, but did re-route them together for most of their length. I would imagine that the metalclad box should go someway to containing and constraining any stray magnetic flux.


The boxes aren't quite so wonky in real life, that is just a camera lens bending the image a little...
 
To be pedantic they should be through the same knockout. If they are going through separate holes you can cut a slot in the metal to join the holes together. You still need to maintain an IP4x rating though! For the amount of current flowing though the cables for a hifi I doubt it will be very detrimental however I like to see things done right - working in a highly regulated industry too :LOL: .
 
What is the point of coming on here, asking for expert advice and then not following it.

Hi-Fi CU Rev 3. wiring re-routed properly this time :D
 
The actual main bonding cable from the gas main was left off by the guys who installed the gas central heating a few years ago. I employed a very well regraded local Corgi registered installation company ( now part of the Nationwide gas care Network - and not the cheapest quote either ! ) and not knowing anything about Gas central heating at the time just trusted that they would do the job properly, just goes to show what can happen if you blindly trust tradesmen just because they belong to an officially recognised scheme....

Just because someone carries a corgi card, doen't necessarily mean they know what they are doing with gas and electrics.

I have seen many a 'corgi registered' operative who cannot even carry out a simple tightness test :eek:

I don't know what sparks think, but certainly in gas a lot of training centres teach them to pass the exam, rather than know what they are doing :rolleyes:
 

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