CORGI visit - queries on regs


strung

Metal steps set in plastic sides are all the rage currently. I don't see each step being earthed.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
strung

They would not require bonding under the main equipotential bonding rules as, being insulated, they do not qualify as "extraneous conducting parts" - the defintion for which requires that they are "liable to introduce a potential". (They would float)
However, a whole metal staircase indoors would require a main bond in my opinion.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

If so, isn't this unlikely to be at the boiler?

;-)
--
*Some people are alive only because it's illegal to kill them *

Dave Plowman snipped-for-privacy@davenoise.co.uk London SW
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Ah. My original text is a bit ambiguous. Sorry.
The bonding needs to be *between* the CH pipes and the origin of the installation (i.e. CU etc.).
The regs don't specify where the bonding should be attached to the CH pipework (unlike the gas service), but flow & return near the boiler seems as good a place as anywhere. And under the floorboards is best aesthetically.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Fri, 10 Dec 2004 23:09:27 GMT, "Coherers"

Read up on equipotential and supplementary earth bonding, then come back.
--

SJW
Please reply to group or use 'usenet' in email subject
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
strung together this:

I have absolutely no need to, and in the absence of you putting forward evidence to the contrary, I would suggest that perhaps it is someone a bit closer to home in need of some technical training.
As you don't seem to be interested in the regulations, perhaps you would be interested to read what Marks says in the "Handbook on IEE Wiring Regulations BS7671"
<QUOTE> Main Equipotential Bonding
Extraneous conductive parts that extend throughout the installation shall be connected to the main earth terminal at the origin of an installation by main equipotential bonding conductors, including the following items:
1. Main water pipes. 2. Gas installation pipes. 3. Main service pipes and ducting. 4. Central heating and air conditioning systems. 5. Exposed metal parts of the building structure. 6. The lightning conductor system. 7. Metallic sheath of telecommunications cable ( subject to the owner's or operators consent). 8. Extraneous conductive part which is in direct contact with earth. 413-02-02 and the Electricity Supply Regulations.
</QUOTE>
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
strung together this:

be
be
Yes
Not a gas expert but I assume this is correct

No - most ducting is floating and totally safe. If he means exposed ducting I might agree more.

Basis of this argument but shall we say some do, some don't.

No. Have you ever seen a Juliet balcony earthed for example ? Far safer unearthed I would think.

No !

Absolutely not !!!!!

Surely this would form an earth path you may not want in a PME system

All in all, you don't appear to be quoting from a reliable source. Perhaps a new handbook from a better author is required.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Perhaps
Trevor E. Marks has written courses on behalf of the IEE, has been chair of IEE technical sections and is a well known respected technical author who has written extensively on electrical subjects.
So what we have is that you think:
1) The clear quote from the IEE wiring regs is wrong. 2) A standard, well-known text, which you appear never to have heard of, is wrong. 3) A document on the IEE web-site, written by Paul Cook ( author of the IEE publication "Commentary on IEE Wiring Regulations" and who gives papers on the subject at international seminars) is wrong. 4) Engineers discussing it on the IEE web site who are also wrong.
I am sorry you don't agree with the IEE, but I am afraid they make the regulations. Take it up with them.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

of
Even if we ignore the contentious items, he is wrong on both the lightning and telecomms points. These are serious mistakes.

There are errors in all standards. They are the work of teams of experts usually volunteered by their companies who make a 'best-effort' on the task in hand. I have contributed to many such forums in the telecomms fields and I am sure these contain errors as well.

is
I'm an electronics engineer, not an electrician, and so a book on the wiring regs don't come high on my list of preferred reading. I doubt if he has heard of me either.

IEE
Quite possibly. I am often critiquing papers at seminars and find glaring errors.

As a member of the IEEE I don't think I can get to these. But I'll see if it's possible.

Don't agree with many things about the IEE, that's why I joined the IEEE 25 years ago.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

IEE Wiring regs have required bonding of lightning conductors for years. I believe the BS on lightning conductors does too, but I don't have a copy of it to see exactly what it says. Many electricity suppliers will refuse to connect you to the supply if you have bonded the lightning conductor. Thus it has never been possible to make it conform to all the various regs.
Bonding of telecoms equipment is a horribly complex area, particularly if you manufacture it for sale to multiple countries/PTTs. In just about all cases, it has to be bonded, but it is often done at a single point only, and kept isolated everywhere else. PTT's normally have their own wiring regulations and are often exempt from national wiring regs and EU directives on things like emissions.
--
Andrew Gabriel

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Agreed - it is NEVER bonded at the terminal (user) end. To do so could mean a lightning strike to your incorrectly bonded lightning rod, or just to the overhead mains cable feeding your house, taking out a whole central office.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

who
On the telecomms side he does say that it requires the permission of the owner/operator which I doubt would be forthcoming. However, from the *purely* electrical safety point of view (as opposed to concerns about how you affect the telco equipment etc. ) it is consistent with the general approach of bonding extraneous metal parts.
On the lightning point, as I said in an earlier post, I don't really see where the need would arise anyway - but it *is* what the IEE Regs/OSG etc, etc. say, as well as Trevor Marks. As for whether it should be removed, I don't feel qualified enough to say for sure.

task
and
Ah! I don't have any problem with the possibility that the standards **may** be wrong. Indeed, I understand there were bits introduced into the 15th edition that were taken out in the 16th because they were no longer believed to reflect best practice. But, my problem is that I don't know the subject area in enough detail to overturn the IEE view; nor do I have the time to get to the point where I do. And if I am going to second guess a committee of individuals brought together to produce the standard I am going to have to be pretty expert in arguments for and against. My other problem is that 7671 has a certain quasi-legal force. Deviating from it and then trying to argue that it is wrong when you are being sued/prosecuted won't get you far.

wiring
on
Sure, errors occur in papers. But for the error to have reached British Standard status and to have gone unchallenged for over 12 years (a period in which loads of amendments have been published) is not likely. They obviously believe this is best practice.

Well, why don't you stir up the IEEE to put the case to the IEE about how some clauses in the regs are liable to result in damage to electronic equipment? I.e. get the IEEE to start representing the interests of *its* members in the standards process. You can't blame the IEE for putting this stuff in if nobody with a different perspective puts the other side.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

You've hit the nail on the real problem. Until Jan 1st I can quite legally argue that my way is better and provided I can convince an independent third party chartered engineer of this I can do as I wish. But with Part P this becomes a whole different issue. However if a BCO tells me to bond boiler pipes on one of my developments then this may well be heading to court.

25
The IEEE is an US led 'worldwide' body who issue a set of regs based on 110v mains. If they were allowed to enter the fray they would argue for this to be adopted worldwide, probably not the discussion needed here.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Fri, 10 Dec 2004 18:28:08 +0000 (GMT), "Dave Plowman (News)"

I have worked with some plumbers and electricians who haven't got a clue so just bond everything in sight with 10mm so they've got to be covered. Unfortunately, in most cases they made it worse by mixing equipotential zones.
--

SJW
Please reply to group or use 'usenet' in email subject
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Well, I did cross-bond these 5 pipes - reckon it took less time to actually do it than to read all the conflicting responses here :-) . However, from what you're saying above, could it in fact be a Bad Thing to have fitted it? Not sure about this issue of mixing of equipotential zones...
The sparks was round yesterday to do a full check on all my electrics in fact, and didn't pass any comment on any of the cross-bonding.
David
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

GSIUR 26.6 - No person shall install an appliance without the means to isolate it from the gas supply.

I'd agree with you there Ed. The issue of accessibility is a bit vague here but since its adjacent to a screwed coupling to the hob itself the implication to me at least is that it must be OK

Especially since the use of plastic water carrying parts in many boilers effectively isolates one pipe from another via the boiler so its sensible to ensure that the pipes are equipotentially bonded at this point
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

inspection,
If you want to remove the hob, you also need to remove the built-in oven to get at the fixings. So the isolation valve can be in the void at the back of the oven without any fuss, because it's there when you'll need it the most. In a case of a gas leak or severe hob fire, I'd rather everyone turned the mains cock off at the meter, rather than trying to isolate each appliance separately.
The earth bonding is needed as part of the electrical safety requirements for the boiler, that's if you or your electrician think it's needed or not. If any faults occur in or around the boiler that could create electrical arcing to the pipework, then the earth bonds are there to try and prevent this happening.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

not.
But most boilers have a single safety earth connection point. Using this automatically earths the pipes (why 5 ?) so what's the point of adding bonding to each ?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

CH Flow, CH Return, Mains water in, DHW out, Gas in?
Alternatively,
CH Flow, CH Return, HWC Flow, HWC Return, Gas in?
Christian.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
writes

The electrical connection of the pipes by the boiler metalwork is an incidental one which cannot be relied on for safety purposes eg. a fitting may be bolted to a painted case and the fixing normally breaks through the paint but it cannot be guaranteed to. Similarly for electrical links through screwed plumbing connections with sealant applied. The bonding has the sole purpose of being safety electrical connection so it makes a guaranteed connection.
--
fred

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.