Supplementarty bonding to bathrom

[Desie]

Guys

I have just inspected a house and found that although the bonding was fine there was no earth continuity to the copper pipes in the bathroom. I am assuming that the water and CH system is broken soemwhere with plastic piping.

Obviously the copper needs supplementary bonding but without causing major disruptin to a house that appears to have been re-furbished I need to earth the pipes. There is a socket on the hall wall outside of the bathroom.

Is it within regs and reasonable to earth to this point?

 

[jj4091]

No! & having just read your other post I am wondering what you mean when you say" I have just inspected a house". You are obviously not qualified to be carrying out electrical inspections or instalation work,especially on a fee paying basis.

 

[Desie]

JJ on what basis do you make your assumption?
What qualification do I need to inspect a house for faults or issues?
Any tom dick or harry can carry out an inspection.

Reading some of my posts is a ridiculous way of judging me. I am a recently qualified electrician and sometimes seek some clarification that what I am doing in practice is correct. Hence the reason some of my questions are deliberately made to be a little niaive sometimes.

Why am I justifying myself to you I ask myself? I have the same qualification as many others out there, have NIC accreditation and Part P registered. If I was straight from college or a C&G course I would still have the same qualification to do the work but with no experience of 'real situations' would find myself day after day questioning what I was doing.

On testing the bathroom for earth continuity there was no reading. Supplementary bonding according to the on site guide can be obtained using circuit protective conductors (Section 4d), the nearest of which is on a socket outside the bathroom.

My question was a legitimate one based on low level experience and information available. If you can't be bothered to give me a sensible answer then please take your arrogance elsewhere and let someone with some tact give me a sensible answer. Or do you wnat to give the benefit of your................ experience?

 

[sm1thson]

read up on the earthing and bonding (they are different). looks like you need more info on the latter, theres some good info in the wiki.

 

[Desie]

Smithson

There is info on ikipedia for earth bonding but not specifically supplementary bonding.

With all due respect but I know what the difference is. The question is was I taught correctly on my original course 2 years ago, am I reading the OSG right and more improtantly am I protecting my customer the way I should be doing?

Correct me if I'm wrong but supplementary bonding provides earth protection in the case of a fault and the copper pipes coming live. the earth path would normally be provided via bonded water pipes extending via the propertys network into the bathroom. Supplementary bonding of the pipes and appliances around the bathroom provides extra protection particularly for pipes that are not covered under the bonding.

If no earth path exists within the copper pipes in the bathroom then surely we have to find or create one?

Please correct me if I'm wrong.

 

[JohnD]

The point of supplementary bonding is to bring all metalwork that might introduce a potential, to be at the same potential.

So even if, by some mishap, the hot water pipe was at 220v+, it would do you no harm to touch it, and the cold tap at the same time, because it would be at the same potential, so no PD between them, so no current will flow through your body from one to the other.

Same with the metal bath and the iron soil pipe, or the lead waste to the basin, and the radiator.

(Hopefully, if such a fault did occur, the overcurrent protection would quickly trip in most conditions, but the equipotential bonding will protect you even if it doesn't)

 

[Spark123]

Wikipedia, wash yer mouth out!!
Clicky

 

[Desie]

John D

Thanks for that explanation an it sort of supports what I already believed to be true however your last sentence in brackets is my issue. There is no evidence of equipotential reaching the bathroom probably due to sections of plastic pipe somewhere in the housebreaking up the metal pipe circuit.

Do I therefore need to earth the bathroom piping system via a cpc?
and
Can I use the socket on the opposite side of the wall as that cpc?

Thanks for your help.

 

[jj4091]

Any tom dick or harry can carry out an inspection.

Only if they know how to rectify any problems!

 

[bernardgreen]

There is no evidence of equipotential reaching the bathroom probably due to sections of plastic pipe somewhere in the housebreaking up the metal pipe circuit.

"equipotential" doesn't need to reach the bathroom as each room has its own "equipotential" voltage.

Provided all metal work in a room is at the same potential you could have the main bathroom all equipotential to earth, the ensuite equipotential to 230 volts and other special areas equipotential at other voltages.

As long as all metal in a room is close enough in voltage to all other metal in the room so as to prevent electric shock danger then equipotential has been achieved.

Sounds stupid to write it like that but that is the hub of the matter.

 

[sm1thson]

With all due respect but I know what the difference is.

with all due respect you original post didn’t sound like you do, when you wrote:

I need to earth the pipes. There is a socket on the hall wall outside of the bathroom. Is it within regs and reasonable to earth to this point?

now:

The question is was I taught correctly on my original course 2 years ago, am I reading the OSG right and more improtantly am I protecting my customer the way I should be doing?

the answers are
was I taught correctly on my original course 2 years ago –yes (well I’m pretty sure you would have been)

am I reading the OSG right and more improtantly am I protecting my customer the way I should be doing? -no

You really need to understand what Bernard is saying. and the link in the DIYnot wiki is a good explanation of how to efficiently and effectively do the bonding within the bathroom, most bathrooms Ive seen have more than required or not as much as required rarely done correctly (although thats just what i see in my travels Im not a spark)

 

[mikely]

The purpose of supplementary bonding is not to provide an earth for the pipework, so you should not just connect the pipework to any convenient CPC. Supplementary bonding eliminates a hazardous voltage that could develop between exposed conductive parts on different circuits or between an exposed conductive part and an extraneous conductive part during an earth fault. See Figure 1 and the description in this new article by the IET: equipotential bonding.

The supplementary bonding is to connect together all CPCs of circuits entering zones 1, 2 or 3 with extraneous conductive parts (On-site guide Fig 4d). If there are no extraneous conductive parts, all CPCs of circuits entering zones 1, 2 or 3 are still to be connected together (On-site guide Fig 4e). If there are no circuits entering the zones, you do not need any supplementary bonding.

 

[scousespark]

JJ on what basis do you make your assumption?
What qualification do I need to inspect a house for faults or issues?
Any tom dick or harry can carry out an inspection.

Inspection and Testing requires a high level of knowledge. A PIR is not something 'any tom dick or harry' usually does. There are a lot of real electricians who don't I&T (as in PIR) because of the implications of doing the job. As for qualifications, most of us regard 2391 as the standard.

 

[oggers]

Desie: I think Mikely has summed things up for you regarding what you should be trying to achieve.

Whether your original proposal will achieve proper supplementary bonding (not exactly what you asked I know) is doubtful based on the amount of info you gave. That doesn't rule out your proposal of using the socket as a means of acheiving that. But, as I see it, that would be pointless unless cpcs of any/all ccts supplying services in 'zones' are also connected to that point 'locally' in a suitably direct manner and not just via the MET.

 

[securespark]

There is a socket on the hall wall outside of the bathroom.

Is it within regs and reasonable to earth to this point?

What qualification do I need to inspect a house for faults or issues?

I am a recently qualified electrician

With respect, Desie, I am a little concerned that, being a recently qualified electrician, you should be asking these questions.

You know about supplementary bonding, surely? And the requirements for a PIR?