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Topic Title: Mobile Home
Topic Summary: Bonding requirements as normal?
Created On: 27 April 2013 12:50 PM
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 27 April 2013 12:50 PM
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Zs

Posts: 3005
Joined: 20 July 2006

Afternoon,

I visited a Mobile home installation which had no bonding to gas or water and various other issues.

For information, the gas is supplied from large calor gas containers dotted around the park. Each home does not have its own calor gas supply, it is communal.

Apparently the installer, who does most of the gas and electrical work on the park says that water and gas bonding is not required. The water is plastic incomer and the gas is metal.

I'm looking for him to be correct but I'm not finding it. Section 721 states that normal regulations apply for mobile homes.

But, I'm not familiar with communal calor gas supplies so I'm checking with you in case I'm missing something.

Zs
 27 April 2013 01:16 PM
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alancapon

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Don't get too confused about the gas containers. If you have a metal supply pipe which goes into the ground, it needs bonding. If there is more than one property connected to the length of metal pipe, it requires bonding. Treat it as a normal gas supply, and pretend you haven't seen the large tanks!

Regards,

Alan.
 27 April 2013 03:59 PM
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dbullard

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Zs, what is the incoming supply ?? is it a park home or a large caravan, I have a site that "Had" calor tanks that wasn't bonded ...... I did bond it my backside on the cert etc.

I also had a very large medieval detached house (on the land a castle ruin from the doomsday book) a few years ago that was on a tn-s supply and when I spoke to a certain technical line about the lack of bonding to the incomer on the calor tank, they were undecided about weather it required bonding at all ................. lets say I did bond it...


Regards

Daren

-------------------------
..... Dont pee in my pocket and tell me its raining ......


www.quest-electrical-sw.co.uk
 27 April 2013 04:38 PM
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weirdbeard

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Hi Zs, probably not much help to your conundrum but i just found this link from the HSE

http://www.hse.gov.uk/gas/lpg/...icepipework.htm


( Edit: there seems to be a problem with links at the mo, add www. to this:

hse.gov.uk/gas/lpg/servicepipework.htm )


Under the heading 'Materials of constuction' it says:

"If buried pipework is metallic then it will need to be replaced."

Soooo.....it might be the case that there is a danger from the extraneous pipe being unbonded, but it seems there is also a danger that requires the pipe itself replacing with a non metallic one in the near future, so perhaps theres a short-term case for not making any alterations (electrically) to the metallic gas pipe in case it compounds the problem?

Edited: 27 April 2013 at 04:44 PM by weirdbeard
 27 April 2013 11:29 PM
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Zs

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Thank you for the replies.

This kind of thing is such a shame and I was really hoping to be wrong.

Here's a fellow who has a reputation and a thriving little business in a close-knit community where his opinion and workmanship are deeply trusted.

There are some other very serious defects in the new installation I was called to.

Now I have to burst his bubble. It saddens me.

Zs
 28 April 2013 09:32 AM
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Fm

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Should be easy to add a few cables though.
 28 April 2013 10:24 AM
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OMS

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Have you tested both gas and water in the sense of proving or disproving if they are actually extraneous - 23Kohms to the MET for example

With a plastic water incoming supply, it's almost certainly not exraneous and won't need a bond.

If the gas supply is metallic, it almost certainly is extraneous and as such will need main bonding as normal

If you bond the gas, and water is close, then a single conductor from the MET to gas and a loop to the water is sensible.

WRT to replacing metallic pipework, I wouldn't pay too much attention to that - HSE are trying to resolve a much more significant issue of corroded steel pipework resulting from the investigaton into the Glasgow plastics factory incident which killed 9 people and criticaly injured many more.

First decide if the pipework is actually carbon steel, not copper - the risk is one of corrosion - the former will, the later very rarely.

Apparently the installer, who does most of the gas and electrical work on the park says that water and gas bonding is not required. The water is plastic incomer and the gas is metal.


Incorrect - the gas almost certainly requires bonding (unless he has a sneaky section of "flexible" pipe tucked away under the floor of the portacabin) effectivley breaking the metallic pipe - but that presents another issue.

Here's a fellow who has a reputation and a thriving little business in a close-knit community where his opinion and workmanship are deeply trusted.


Deeply trusted because they've probably never been challenged - I've listened to the most farcical rubbish being trotted out by people who have assumed everyone else in the room is less technically competent - ans being readily believed by people who really should know better
.
It's why it's handy not to have your post nomials plastered over every bit of correspondence and to be non comittal about your job description - that way said "trusted professionals" assume everyone else is a stupid as the belive then to be.

Now I have to burst his bubble. It saddens me


For sure - but you have a client you owe a duty of care - if that duty of care ends up bursting someones bubble, it's not personal. Just be factual.

Regards

OMS

-------------------------
Failure is always an option
 28 April 2013 12:23 PM
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dbullard

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Originally posted by: OMS

Have you tested both gas and water in the sense of proving or disproving if they are actually extraneous - 23Kohms to the MET for example



With a plastic water incoming supply, it's almost certainly not exraneous and won't need a bond.



If the gas supply is metallic, it almost certainly is extraneous and as such will need main bonding as normal



If you bond the gas, and water is close, then a single conductor from the MET to gas and a loop to the water is sensible.



WRT to replacing metallic pipework, I wouldn't pay too much attention to that - HSE are trying to resolve a much more significant issue of corroded steel pipework resulting from the investigaton into the Glasgow plastics factory incident which killed 9 people and criticaly injured many more.



First decide if the pipework is actually carbon steel, not copper - the risk is one of corrosion - the former will, the later very rarely.



Apparently the installer, who does most of the gas and electrical work on the park says that water and gas bonding is not required. The water is plastic incomer and the gas is metal.




Incorrect - the gas almost certainly requires bonding (unless he has a sneaky section of "flexible" pipe tucked away under the floor of the portacabin) effectivley breaking the metallic pipe - but that presents another issue.



Here's a fellow who has a reputation and a thriving little business in a close-knit community where his opinion and workmanship are deeply trusted.




Deeply trusted because they've probably never been challenged - I've listened to the most farcical rubbish being trotted out by people who have assumed everyone else in the room is less technically competent - ans being readily believed by people who really should know better

.

It's why it's handy not to have your post nomials plastered over every bit of correspondence and to be non comittal about your job description - that way said "trusted professionals" assume everyone else is a stupid as the belive then to be.



Now I have to burst his bubble. It saddens me




For sure - but you have a client you owe a duty of care - if that duty of care ends up bursting someones bubble, it's not personal. Just be factual.



Regards



OMS


OMS and Zs, form my limited past experience all of the calor gas installs similar to this have been in carbon steel with the tank on a concrete plinth with pipe work being underground.

Regards

Daren

-------------------------
..... Dont pee in my pocket and tell me its raining ......


www.quest-electrical-sw.co.uk
 28 April 2013 12:39 PM
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OMS

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OMS and Zs, form my limited past experience all of the calor gas installs similar to this have been in carbon steel with the tank on a concrete plinth with pipe work being underground.


Agreed - we just don't know, nor is it relevant really - steel or copper will both be extraneous parts.

In terms of a replacement programme - there probably won't be one - from HSE's perspective they have no real jurisdiction as these are domestic dwellings.

Equally, they would only have any real concerns if the building is public, contains a number of people and has basements.

Currently, it sound as if it's extraneous, un bonded and the local "fellow who has a reputation" is about to get his rep torn to shreds. What happens sometime in the future or never isn't really part of the debate

regards

OMS

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Failure is always an option
 28 April 2013 05:39 PM
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dbullard

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Hi OMS

The reason for the post about differing metals in the ground would be the resistance to corrosion and impact damage, I know the OP was regarding the bonding of, but I seem to remember speaking to a "Calor" chap and their requirement for steel in the ground and impact resistance and the fact it can be. "Screwed together"

Back to the original posting If the main incoming gas is bonded at the tank say, would it also require bonding at each and every "Tap off" if each home has a mains fed electrical 230 / 240v supply

If the tank is shared between a number of homes on this site then it would stand it is no different to a mains gas network and then each home should have a main equipotential bond to the incoming gas supply ???? if in this case where Zs states no main bonging to the "Tank " then what is the chance of the "Home" not having bonding ?? As previously stated the "original" installer argued that it was not required to bond the mains tanked gas supply to the tank.

Sorry to throw a spanner in the works Zs ............

Regards

Daren

-------------------------
..... Dont pee in my pocket and tell me its raining ......


www.quest-electrical-sw.co.uk
 28 April 2013 05:50 PM
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jcm256

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Dear Zs, why did you ever leave the kitchen and get letters after your name, and now involved in this entire consultancy and regulated stuff.

You say mobile homes, so would that unlikely to be a fixed pipe right into the homes and the final connection be a flexible gas hose. (Not sure if are you talking about earthing the service pipe or installation pipe work). But however,

Again unlikely the supply is TNS or TNCS but TT or separated TT, so by bonding, you would be connecting the one LPG gas (service) pipe or (service) pipes to the main consumers earth electrode or each individual homes earth electrode. .

It is difficult to grasp the meaning in gas regulations on earthing, they are committal of course on cathodic protection, but service pipe work earthing?



If you look at page 72 on this site below

Abstract:
This guidance does not apply to domestic premises, including distribution networks and service pipework supplying residential caravans. However, LPG supplies to any communal buildings on caravan parks will be within scope as commercial LPG installations

"><br ">http://.....nte...ect/lpg.pdf



http://www.hse.gov.uk/foi/inte...s/fod/inspect/lpg.pdf

Note:
Tanks and pipework shall be predominantly painted as follows:

LPG - gloss white

Natural gas - light buff (BS 5252 colour 08C35).

Colour reference: 08 C 35

Description: Fudge / Butterscotch / Bamboo

(Sorry about the fudge reply)
Regards
jcm

Edited: 28 April 2013 at 05:57 PM by jcm256
 28 April 2013 06:09 PM
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dbullard

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Originally posted by: jcm256

Dear Zs, why did you ever leave the kitchen



I'm ducking behind the parapet..................

-------------------------
..... Dont pee in my pocket and tell me its raining ......


www.quest-electrical-sw.co.uk
 28 April 2013 06:11 PM
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OMS

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Originally posted by: dbullard

Hi OMS

The reason for the post about differing metals in the ground would be the resistance to corrosion and impact damage, I know the OP was regarding the bonding of, but I seem to remember speaking to a "Calor" chap and their requirement for steel in the ground and impact resistance and the fact it can be. "Screwed together"

yep - the gas guys like steel, but the clients often ignore itto the oint of it rusting away and leaking - which is generally what killed 9 people up in Glasgow. Intersting debate - not really relevant here though


Back to the original posting If the main incoming gas is bonded at the tank say, would it also require bonding at each and every "Tap off" if each home has a mains fed electrical 230 / 240v supply

It would yes - its (the bondings) purpose is to create an equipotential zone withing the portacabin - it can oly achieve that if it's bonded as it enters the portacabin

If the tank is shared between a number of homes on this site then it would stand it is no different to a mains gas network and then each home should have a main equipotential bond to the incoming gas supply ????

Exactly
if in this case where Zs states no main bonging to the "Tank " then what is the chance of the "Home" not having bonding ?? As previously stated the "original" installer argued that it was not required to bond the mains tanked gas supply to the tank.

I don't think Zs said that - a bond at the tank woul be pointless - what zone could you hope to achieve externally. It may be earthed for other reasons but that's not the debate here.

The point as I read it is that the mobile home is connected to a communal LPG system (presumed via a meter that's not insulating) and isn't bonded - hence my initial comment regarding "have you tested it" - and if so ha the local expert done something sneaky like an insulating

That's not to say I read it correctly though


Sorry to throw a spanner in the works Zs ............

Regards

Daren


regards

OMS

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 28 April 2013 06:34 PM
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dbullard

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I read it the same way OMS but !! i am wondering if Zs has confused calor and propane tanks ...................... if propane then no bonding is required as they are fed via a purpose made hose and regulator on each and every home so would have no contact with earthy potential, thus not requiring a equipotential bond, if the home is the conventional static caravan type then these usually also have a wooden frame mounted onto a galvanised chassis and mounted off the ground usually on concrete blocks to level them out and gain more room under the van / home.

I had asked the question on one of assessments, and was given the above answer, so I would assume it to be correct, but assumption is the mother of all #######


Regards

Daren

-------------------------
..... Dont pee in my pocket and tell me its raining ......


www.quest-electrical-sw.co.uk
 28 April 2013 06:43 PM
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OMS

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Originally posted by: jcm256

Dear Zs, why did you ever leave the kitchen and get letters after your name, and now involved in this entire consultancy and regulated stuff.

Mmmm - because it's the career path chosen - bumps in your jumper doesn't preclude a brain that deals with problems now does it


You say mobile homes, so would that unlikely to be a fixed pipe right into the homes and the final connection be a flexible gas hose. (Not sure if are you talking about earthing the service pipe or installation pipe work). But however,

Indeed - many "statics" have a hard pipe supply though - all that's being discussed here is the question of is it earthy


Again unlikely the supply is TNS or TNCS but TT or separated TT, so by bonding, you would be connecting the one LPG gas (service) pipe or (service) pipes to the main consumers earth electrode or each individual homes earth electrode. .

Not relevant - the earthing type is not a consideration - ADS requires bonding of extraneous services - be they water, gas of any nature, oils, compressed air, ductwork or even the infamous silver stake driven through the floor into the ground - if it can introduce a potential than it needs bonding


It is difficult to grasp the meaning in gas regulations on earthing, they are committal of course on cathodic protection, but service pipe work earthing?

You are, I think getting the wrong end of the stick - extraneous part enters property - BS 7671 says bond it

If you look at page 72 on this site below



Abstract:

This guidance does not apply to domestic premises, including distribution networks and service pipework supplying residential caravans. However, LPG supplies to any communal buildings on caravan parks will be within scope as commercial LPG installations



">"><br ">&l.......nte...ect/lpg.pdf



]http://www.hse.gov.uk/foi/internalops/fod/inspect/lpg.pdf
<br [/L]



http://www.hse.gov.uk/foi/inte...inspect/lpg.pdf



Note:

Tanks and pipework shall be predominantly painted as follows:



LPG - gloss white



Natural gas - light buff (BS 5252 colour 08C35).



Colour reference: 08 C 35



Description: Fudge / Butterscotch / Bamboo



(Sorry about the fudge reply)

Regards

jcm


Regards

OMS

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 28 April 2013 06:54 PM
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OMS

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It's why I suggested testing it Daren - I've seen some plumbed in via a regulator in "hard" pipe work - others via flexible that may be insulating - but very often the flexible is stainless steel braided anyway.

the same may be true for any metering that's in place.

It'll depend on the nature of the gas being supplied from the bulk storage tank i guess - or a quick look behind the caravan "skirt" to see what's there.

I'm guessing it is extraneous though - one of Zs's famous 50p bets on it -

Regards

OMS

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 28 April 2013 09:00 PM
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jcm256

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Originally posted by: jcm256

Dear Zs, why did you ever leave the kitchen and get letters after your name, and now involved in this entire consultancy and regulated stuff.
.....................................................................................................................
Did not mean it like that, just a dash of humour, maybe was thinking of myself was happier on the tools. It is complex job of seeking, clarifying, verifying, and evaluating facts in the world outside the kitchen installation. The wording require a little re-arrangement, apologise

Regards
jcm
 28 April 2013 10:04 PM
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Zs

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Now, this has all become very complicated but I think I now know that there is no special mention in big green of mobile home parks with communal gas supplies not requiring bonding and the home not being an equipotential zone. That'll do for me.

Not wishing to sound as though I'm picking out curtains or anything but the tanks are a kind of eau de nil colour, or perhaps a pale yucky beige/green with a pleasing tinge of iridescence at twilight, slight and not overdone distressing and a tiny hint of verdigris. The concrete plinths provide a dramatic contrast to the smoothness of the tank paintwork with their rugged edges and ridged appearance which is quite charming.

And the pipework, oh you should see it in the sunshine just at the point where it emerges from the ground beside the mobile home, you would almost believe it to be made out of copper.

I agree that the addition of a piece of flexi pipe just on entry to the home and before the gas meter would have been a nice touch but alas, there isn't one and the opportunity for a striking juxtaposition has been missed. To compensate for that not being there though, you may look at the 40A cooker connection into the back of a radial socket circuit in awe or comment on a split load board with all of the power on one RCD and all of the lights on the other side. I would have preferred a more gentle mosaic effect myself and would have done it that way....

But I was busy making jam for a competition on the day that was done and it took ages to attach the little checked tops to the jars....


Zs

Edited: 29 April 2013 at 06:40 PM by Zs
 28 April 2013 10:41 PM
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dbullard

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So Zs apart from the mosaic effect of your "Jars"we can concur that you have a Propane installation with a lovely verdigris copper underground - overground type installation ..... with a stunning summer glow of copper arising from the ground into ones "mobile home / static caravan.

Sounds a little "Ropey" to me with copper and gas underground, I have seen what an acidic soil can do copper pipes let alone an earth rod made of steel covered in copper.

If I had come across this installation and it was TT I would be very careful where I would be sticking my earth rods in if they were / are required.

TTFN

Regards

Daren

-------------------------
..... Dont pee in my pocket and tell me its raining ......


www.quest-electrical-sw.co.uk
 29 April 2013 10:39 AM
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AJJewsbury

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significant issue of corroded steel pipework

I can back that up. Several years ago, BG/Transco came to do a routine replacement of the gas meter. I'd noticed that the gas pressure at the cooker dropped a bit whenever the boiler fired up, so I asked them if the could check the regulator at the same time. One pressure test and a bit of swearing later they were on the verge of cutting off my gas supply there and then. Next day they were back to dig up half the garden and replace all the buried steel pipework all the way back to the street. It seems that the steel gas pipes rust from the inside (presumably some reaction between the gas and the metal) and literally get clogged with rust.
- Andy.
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