Equipotential bonding satisfactory - No

[fatbob88]

That title describes one of the entries on the landlords gas safety certificate for my home. (I had the central heating boiler serviced at the same time, the reason for the gas safety cert. is because I may be moving out and letting soon). In the details of faults column the engineer has stated that there is no earth cross bonding within 600 mm of the gas meter and advises to have it rectified.

I have lived in the property for 17 years and there has never been earth bonding next to the gas meter. In 2002 I had planned on letting out the property so I called in a qualified electrician, told him of my intentions and had him do the work required to bring it up to the standards required at the time. Funnily enough most of the work he did was to do with earth bonding i.e. replacing earthing on main incoming cable to the consumer unit, installing main earth bonding to the gas and water services and supplementary bonding to other pipework e.g. hot and cold water pipes and sink etc. When he was finished there was earth bonding just about every where I looked where there was copper pipeing, including in the loft.

Anyway to cut a long story short I am wondering whether I really need to get this done. Let me explain, the gas meter is in the corner of my kitchen and sits on the floor inside a kitchen cupboard, part of the floor of the cupboard has been cut away to accomodate for it. On the output side of the meter a flexible pipe with a tapered end is connected into the top of what I would describe as a metal "T" on it's side. If you look at it as a "T" on its side the lower vertical branch is anchored into the concrete floor, the top of that vertical is where the flexible pipe comes in and the horizontal piece is where the gas goes to the copper pipe run which supplies the central heating boiler. As the "T" arrangement is anchored into the concrete floor does this not dispense with the need for earth bonding?

If it's of any use I have a Hager CU with all circuits being protected by MCB's or are they RCD's (same thing I think). Anyway, they are of the switch variety which trip upwards I believe when their is an earth leak.

Advice appreciated, thanks.

 

[Lurch]

Whether the pipework is buried in the ground or not makes no difference to whether it needs bonding or not.

In 2002 the regulations still required a bonding connection within 600mm of the meter so you either need another electrician or to do some more checks. Is there a connection on the gas pipework anywhere near the meter at all of any size\shape\age?

 

[m4tty]

Mcb' and rcd's are different and are you saying there's no green/yellow cables goigg for consumer unit to gas pipes and water pipes. A picture of the outgoing cables from the consumer unit would help. Cheers

 

[monkey5]

hi, MCBs and RCDs arnt the same, rcds have a test button as trip for a different reason. might be worth posting some pics if you can.

HTH wayne

---------- AUTO MERGE Post added at 20:13 ---------- Previous post was at 20:09 ----------

snap matty

 

[sparkytim]

Hi

It can be a confusing but the Bonding of the Gas pipework is not to connect it to earth but back to the ELECTRICAL earthing point at the Consumer Unit position to ensure your Pipes are at the same potential as all other metal work so you will not get a shock when touching two parts at the same time i.e. Boiler and washing machine metal work.

If a competent electrician did this for you then it should be accessible to see and test, sometimes it may not be visiable, I have often been called to check that a Bond is in place to find it has been connected under a floor out of sight just inside from the Gas meter box which is outside.

The Wiring Regulations require it to be within 600mm Of the Meter OR at the entry point into the buliding BEFORE any branch in the pipework.

It may be good to get a competent Electrician in to check this for you and explain things further, such as the difference between MCBs and RCDs, they are very different and provide protection for different types of faults.

 

[fatbob88]

Thanks for the replies folks, I think we may have a result here thanks to you.

First of all I must say I live in an upstairs purpose built maisonette, you know the type two upstairs and two down, they look like a semi detached house at first sight. The gas pipe for the CH boiler runs across the loft as does the water and other central heating pipes and obviously the lighting circuit.

I've just traced a thick earth bonding cable clamped on the the main earth where the supply comes into the property - near the leccy meter - the other end is clamped to the gas pipe run supplying the CH boiler. It is clamped near to where the pipe exits from the kitchen ceiling and into the loft. Another earth bonding cable comes off of this clamp onto the main water supply to the water tank and further cross bonding from this pipe is in place to the other pipes in the loft. The pipe run from the gas meter or the "T" arrangement as I described above runs vertically up the wall in the corner of the kitchen and into the loft space. It is only partially visible and the first 600mm is not visible or accessible as there is a tall kitchen unit which does not fit right into the corner of the kitchen and the small gap which was left in the corner is where the pipe runs. The tall kitchen unit was cut to accomodate for the pipe run and the space left between the wall and the unit is filled with a plynth. The supply pipe which runs from the horizontal part of the "T" runs a short distance in this inaccessible place but then turns back into the cupboard space further up before exiting into the loft. It would not be possible to bond within 600 mm unless the clamp was on the "T" or the flexible pipe coming out of the meter. The kitchen was fitted in 1993 and as I said before there was no main earth bonding or any for that matter at that time, the property was built in 1959

Hope I've explained that clearly for you to advise me.

Thanks in advance.

 

[Lurch]

Sounds reasonable then. Still worth getting an electrician on the case to get you a report done for the renting. As you are probably aware you have to do the gas but not the electrics, it's down to the morals of the landlord.

 

[fatbob88]

Thanks for the reply Stuart.

I've just been in the cupboard where the gas meter is located to measure the distance of the exposed pipe run from the meter and realised that I've been thinking of 6 cms instead of 60 cms so there is in fact pipe exposed that can be bonded within 60cms.

I appreciate your comment about getting an electrician in to check things out before letting, which I will do. Do you still think it would be best to rectify the situation, I can't see what a little extra distance from the meter would make? Would I be correct in saying that it is not notifiable so I will be allowed to do the job myself?

Cheers

 

[kme]

If I read your description correctly, you have one earth bond going between these various pipes? That would not be the usual way for this to be done - without seeing the install it is difficult to ascertain exactly.

When you say the Tee branch is connected to the gas meter with a "flexible pipe", could you expand on that? Are you certain that is the outgoing side; as flexible connections are usually only fitted to the supply side, IME.

Think it would be prudent to seek professional advice from a reputable local electrician. It can be worth approaching your local network operator, or supplier - some offer free visual checks, which ought to include the bonding.

HTH

KME

 

[Lurch]

If I read your description correctly, you have one earth bond going between these various pipes?

I read it as 10mm (described as a thick cable) ran from the MET to the gas and heating pipes adjacent to the boiler <3m from the gas meter. Not ideal but better than nothing, it would get mentioned on a report as not compliant, but as it stands there would be no major defect notice issued for it, if I have read it correctly that is.

 

[Sidewinder]

I think that this is one of our forum limitations!

We can't see / inspect or assess the actual install.

Thus we must guess!!!

That way we end up not being sure / disagreeing possibly!

 

[fatbob88]

The earth bonding cable is clamped to the main earth terminal and runs up into the loft where it is clamped to the gas supply pipe (the one to the CH boiler) The clamp is located near to where the pipe enters the loft through the kitchen ceiling. It is < 3m from the gas meter as Stuart said. On the same clamp in the loft is another earth cable which runs off and is clamped to the main water supply pipe which feeds the main water tank and the CH feed and expansion tank. The pipes nearer to the main water tank where many of the pipes are in close proximity to one another including the pipes to and from the hot water tank (CH is a conventional boiler not a combi) are cross bonded with the main water supply pipe.

Thanks for your comment KME, just to clarify - both pipes into and out of the meter are flexible i.e. from the main pipe into the property and also into the Tee branch from the meter. The outside diameter of the earth cable is a tad less than 10mm so I guess that it is 6mm cable (assuming that its the core that's measured). I do n't know but was this not the standard in 2002 when it was done?

It's odd but the earth bonding issue around the meter has never been mentioned before when I 've had a CH boiler service? Not that I'm complaining, you can't put a price on safety!

Cheers.

 

[steptoe]

IMHO the regs read to me as 600mm or as near as practically possible, leaves a big hole for whoever wants to make the choice as to practical or not.

remember though that gas regs and electrical regs regarding bonding are different,

you really do need to get an electrician to check this out.

it sounds as though it may be fine to me, but its a site judgement TBH as has been said,

the only worry I have at this stage is to whether or not the earth cable going to the gas and then the water is unbroken or not, going by what has been said it seems like it is a separate cable from gas to water, this would need to be rectified.

HTH

Albert.

 

[fatbob88]

IMHO the regs read to me as 600mm or as near as practically possible, leaves a big hole for whoever wants to make the choice as to practical or not.remember though that gas regs and electrical regs regarding bonding are different,

you really do need to get an electrician to check this out.

it sounds as though it may be fine to me, but its a site judgement TBH as has been said,

the only worry I have at this stage is to whether or not the earth cable going to the gas and then the water is unbroken or not, going by what has been said it seems like it is a separate cable from gas to water, this would need to be rectified.

HTH

Albert.

Thanks Albert.

I've just checked the earth clamp on the gas supply pipe to the CH boiler. On closer inspection I can see the stripped part of the earth cable has been wrapped around the screw which holds the cable down to the clamp. The cable then continues on to the water pipe clamp. Therefore it is one continous cable from the MET and not two as I previously thought. Incidently the core of the earth cable is made up of a number of strands of copper.

 

[kme]

Yup, that is fine as a bonding cable, as far as that goes.

However, you said it is attached to the water pipe in the loft, near the header tank.

It ought to be within 600mm (2ft) of the incoming water supply (stopcock?). Would be worth checking if there is another cable there?

I note you also said the cable was "clamped to the main earth terminal". Could you describe where & what that is, please?

Thanks

KME

 

[steptoe]

sounds OK to me then,

but sounds OK and anything else is two different things, maybe would heve been prudent of your previous spark to put a little label at CU to say where gas etc had been bonded.

otherwise we are in the real world here,

I cant see any major issues with what you have said.

---------- AUTO MERGE Post added at 23:33 ---------- Previous post was at 23:32 ----------

Yup, that is fine as a bonding cable, as far as that goes.However, you said it is attached to the water pipe in the loft, near the header tank.

It ought to be within 600mm (2ft) of the incoming water supply (stopcock?). Would be worth checking if there is another cable there?

I note you also said the cable was "clamped to the main earth terminal". Could you describe where & what that is, please?

Thanks

KME

good points,

:innocent

 

[fatbob88]

Yup, that is fine as a bonding cable, as far as that goes.However, you said it is attached to the water pipe in the loft, near the header tank.

It ought to be within 600mm (2ft) of the incoming water supply (stopcock?). Would be worth checking if there is another cable there?

I note you also said the cable was "clamped to the main earth terminal". Could you describe where & what that is, please?

Thanks

KME

It is attached to the water pipe in the loft near to where it comes out of the soil stack. The mains water supply pipe comes up into the property via the soil stack which is located in the corner of the bathroom. (I'm in a first floor maisonette) The stopcock is located just above floor level in the stack and is accessed through a small hole in the wall by removing a wall tile. It would therefore be impossible to fix a clamp within 600mm unless a chunk of the wall was removed. Bearing this in mind it seems that the nearest accessible place for the clamp is in fact where it is located. Similar circumstances to the bonding on the gas pipe I guess.

Good question about the main earth terminal as I'm guessing I am right about having located it. Let me explain. The MET is in the leccy meter cupboard and is a thick metal bar, I'm guessing 1.5 inches in dia at the end anchored in the ground but it tapers down at the other end which goes inside a brown plastic box mounted on the same board as the leccy meter. There are about three separate brown plastic boxes together each has a wire and lead seal attached. The main supply cables comes in via a pipe (or conduit I believe is the correct terminology) and enter into the plastic boxes I have just described. The conduit is bonded to the MET. Two cables exit from the arrangement of brown plastic boxes and go into the meter and then two cables connect the meter to the CU. Hope that makes sense.

 

[kme]

Let me re-read that in the morning; when I hope to be able to only see 1 post, not 3 Guinness

 

[batty]

Looks like its all hunky dorey apart from main bond is not were it enters property no reason this will need changing as long as there are no plastic in the pipework.

 

[a1]

Hi FatBob,

As suggested, a few photos would've helped a great deal.

With regards to the 6mm main earth bonding - what is the Earthing arrangement of your supply system? (A pic of the incoming supply would help, if you are unsure).

We have a directory of electricians on this forum the main Search and page can be found here:

TEF Directory of UK Electricians

I have done a search using the keyword "Herefordshire" and it has brought up two results:

Electricians that cover work in the Herefordshire area.

There was a few points that I was going to say, but they have already been covered by others here.

Regards,

Admin.