Nice little "Real World" bonding question?

Help Support Talk Electrician Forum:

SPECIAL LOCATION

Trailer Boy - Electrician.
Joined
Mar 28, 2008
Messages
13,633
Reaction score
317
Ok boys, girls, Steptoes, KME's, Pigs, Cows, Admins

or any other combination or permutation thereof....

As Donkeydong would say...... "heres a nice little one for a Friday"..

Although Apache would say ITS still THURSDAY cuz you haven't been to bed and woken up yet.. [but it is 1:30 Friday morning]

so ANYWAY...

did a little domestic PIR earlier this week...

found the following earth bonding conductors....

it reminded me of the sort of thing you would find on a collage test rig for C&G 2391 practical test....

Wylex 4-way CU

{circuit wires disconnected to allow testing & access to earth bar}

Two 6.0mm earth wires onto earth bar..

bottom connection goes to MET on head of incoming PME supply.

Water stop tap under kitchen sink

Two horizontal pipes can be seen One Hot/One Cold!

Two 6.0mm wires connect one to each pipe.

{extra edited info..}

Just to add, the water pipe joint, behind the waste pipe is a 'tee' not an 'elbow'! can be seen better here.

Gas meter in garage

One 6.0mm conductor connected onto outgoing pipe from gas meter.

Other facts..

all bonding was disconnected & long-lead continuity test was carried out to verify which wires go where..

one from CU to sink (water).

one from water at sink to garage gas.

1] How many errors/omissions/non-compliances can you note with this arrangement?

2] How would you leave the installation after completing PIR?

 

moonpig

Senior Member
Joined
Aug 21, 2008
Messages
103
Reaction score
0
Good thread specs;) :) :x , i likes it.

Right well i am off to bed shortly:z, and i have not got a lot of experience testing and i left all my books in work X( (regs, OSG, etc), but i will have a quick go off the top of head before i leave and then come back tomorrow with my real proper answer;) :) .

Now i could well be wrong (wouldnt be the first time;) :) ), but doesnt/didnt 6mm bonding comply on a TT system. Also if not replacing the CU or making any alterations/additions, and the intallation comlpied at the time of install then do you need to upgrade.

As far as action to be taken if the installation failed the PIR i would tell the home owner/customer that it had failed, and that i would do the remedial work if they crossed my hand with silver (or should that be gold;)).

I know i havent answered all your questions but i will have to come back armed with some info after a little research.

 

moonpig

Senior Member
Joined
Aug 21, 2008
Messages
103
Reaction score
0
Goodnight compadre or would you prefer co-cheese:x:x;) :^O :^O

Thanks for letting me play it has been mucho grande funo as usual;) :^O :^O

 

Apache

Cow Fiddler ™
Joined
Jun 21, 2008
Messages
17,011
Reaction score
21
Apache's (amature answer)

I think the water should be bonded before it tees (1)

I thought the bonding should be 10mm (2)

I thought bonding had to be back to CU (3)

Of the 2 clamps under the sink is 1 of those to the CU (cold) and the one on the hot to the gas? If hot and cold not continuous then gas not connected back to CU? There's only 1 wire from each clamp. (4)

We have a missing warning label on the hot clamp and the gas clamp (5 & 6)

Thought the main bonding was supposed to be in 1 continuous run? (7)

Ok apache thinks 7 faults - To mend it, run 10mm from gas to cold water (before it T's) back to CU. Clamps with their warnings on etc. Then test as appropriate :)

CU not complient with 17th but don't think you mean that in your non-complience section.

How did I do? :D

 

mikel

Well-known member
Joined
Jul 11, 2008
Messages
388
Reaction score
0
Location
Bolton
Havng a quick look at the photo's and reference to my NEW on site guide (17th edition) my first thoughts are

The earth bar shud have a 16mm earth to the MET

The main bonding should go to the MET not the earth bar in the CU

Main bonding should be 10mm for it to comply to 17th

Bonding for incoming water supply should be before the T junction and within 600 mm of entering property

Gas bonding should be on consumer side of meter and to 'hard' pipe not the flexible one and go to MET

Do you need to bond the hot water? consideration should be given to whether it would introduce an earth potential and thus is it an extraneous conductive part?

Think I would point all this out to customer and give quoote for remedial work. As a minimum I would connect the existing bonding correctly to MET and pipework as it isn't safe to be left as it is

Lack of experience in inspection and testing stops me getting further into this. There appears to be other defects with wiring in cu but thats a different problem:|

 

norv

Senior Member
Joined
Feb 16, 2008
Messages
126
Reaction score
0
You can get a 16mm in those earth bars. If the tails are 16mm I think you can leave it (I would upgrade it)

Water bond before the 'T' . Should be 10mm, but if customer refuses you can only do what you can do.

Gas should be 10mm with a earth bonding label.

Quote from BS7671: 2008 "Existing installations that have been installed in accordance with earlier editions of the regulations may not comply with this ediion in every respect. This does not necessarily mean they are unsafe for continued use or require upgrading"

 
Joined
Feb 27, 2008
Messages
11,030
Reaction score
0
Looking at photos it looks like there is no main bond to water pipe,

6mm main earth cable is only single colour so does not comply on size and also colour.

Bond to gas is not to current regs and should be affixed to wall.

batty

 

SPECIAL LOCATION

Trailer Boy - Electrician.
Joined
Mar 28, 2008
Messages
13,633
Reaction score
317
C'mon specs - mark us :p
I will mark you Apache .....

once you have got the DON to post another smiley & a KME Guinness drink! :^O :^O:^O:^O] :) ]:) ] :) ]:)

Nah.....

twas only joking!

you are are looking pretty one the ball....

(confirms I have been thinkin on the right lines!! :^O )

I will post some pictures...

and notes a bit later...

; \

 

steptoe

of course Im wrong, ask my wife™
Joined
Feb 13, 2008
Messages
24,422
Reaction score
160
Location
Gtr Manchester
ok, my lappie crashed earlier, heres my solution

gas has no bond at present, so,,,,

through crimp 6mm to water to other 6mm going to gas,

loop through to a cold feed at stop tap then carry on to gas main.

ok, so 6mm is not compliant to 17th, but at least you now have both services bonded, no longer a major, but a minor non complianciance, with the simple use of a through crimp and a BS951 clamp.(or 2?)

am I right, am I, am I , am I, tell tell me , tell me , am I right????????

ps, gas isnt bonded cos its not continuous from the MET, MET can be within the CU, but in this case it is broken by a water pipe, and a different one from the main bond.

 

Apache

Cow Fiddler ™
Joined
Jun 21, 2008
Messages
17,011
Reaction score
21
Mr Steptoe - I can see that if the bonding isn't upto 17th standards but was ok with say the 16th then it's a minor non complience and can be left BUT if you start altering things, as you suggest you surly can't decide to upgrade to whatever set of regs you choose?

It's either left as is - and marked as a major fault or brought upto 17th standards?

 

steptoe

of course Im wrong, ask my wife™
Joined
Feb 13, 2008
Messages
24,422
Reaction score
160
Location
Gtr Manchester
Mr Steptoe - I can see that if the bonding isn't upto 17th standards but was ok with say the 16th then it's a minor non complience and can be left BUT if you start altering things, as you suggest you surly can't decide to upgrade to whatever set of regs you choose?It's either left as is - and marked as a major fault or brought upto 17th standards?
you gonna tell me virtually every house you will work on in the next 10years ish will be a major fault?

not really, it just wont comply to current regs?

and to be honest not many houses at all comply to 16th either, bet I could blow holes in most.

my point is, do your best to make safe, then mark down as non compliance.

EAWR 16

thats the legality of it all.

the law states that you MUST NOT MAKE A DWELLING MORE UNSAFE than when your work commenced, surely helping the bonding is making it more safe.?

BS7671 is NOT law

 

SPECIAL LOCATION

Trailer Boy - Electrician.
Joined
Mar 28, 2008
Messages
13,633
Reaction score
317
ok, my lappie crashed earlier, heres my solutiongas has no bond at present, so,,,,

through crimp 6mm to water to other 6mm going to gas,

loop through to a cold feed at stop tap then carry on to gas main.

ok, so 6mm is not compliant to 17th, but at least you now have both services bonded, no longer a major, but a minor non complianciance, with the simple use of a through crimp and a BS951 clamp.(or 2?)

am I right, am I, am I , am I, tell tell me , tell me , am I right????????

ps, gas isnt bonded cos its not continuous from the MET, MET can be within the CU, but in this case it is broken by a water pipe, and a different one from the main bond.
ah! Mr Step's you is thinking most definitely along the same wavelength as captain Trailer here m8! ;) :x :)Applaud Smiley

 

Apache

Cow Fiddler ™
Joined
Jun 21, 2008
Messages
17,011
Reaction score
21
you gonna tell me virtually every house you will work on in the next 10years ish will be a major fault?not really, it just wont comply to current regs?

and to be honest not many houses at all comply to 16th either, bet I could blow holes in most.

my point is, do your best to make safe, then mark down as non compliance.

EAWR 16

thats the legality of it all.
mate - i'm a vet not a spark. I was just trying to put a point of view. I'm not trying to wind you up :)

 

steptoe

of course Im wrong, ask my wife™
Joined
Feb 13, 2008
Messages
24,422
Reaction score
160
Location
Gtr Manchester
thank you SL,

real world scenario, without the customer having a major heart attack at the extras bill, but still being made aware of the shortcomings of the installation and with the small improvement made.! ;)

 

kme

Fridge Keyholder™
Joined
Mar 7, 2008
Messages
9,987
Reaction score
0
Location
In the office again.
Apache's (amature answer)I think the water should be bonded before it tees (1)YUP

I thought the bonding should be 10mm (2)AH... Probably!

I thought bonding had to be back to CU (3)YUP

Of the 2 clamps under the sink is 1 of those to the CU (cold) and the one on the hot to the gas? If hot and cold not continuous then gas not connected back to CU? There's only 1 wire from each clamp. (4)YUP

We have a missing warning label on the hot clamp and the gas clamp (5 & 6)WOW - YUP

Thought the main bonding was supposed to be in 1 continuous run? (7)YUP

Ok apache thinks 7 faults - To mend it, run 10mm from gas to cold water (before it T's) back to CU. Clamps with their warnings on etc. Then test as appropriate :)

Apache is Very Good. :x

CU not complient with 17th but don't think you mean that in your non-complience section.

How did I do? :D
Gold star, in my book.

Havng a quick look at the photo's and reference to my NEW on site guide (17th edition) my first thoughts areThe earth bar shud have a 16mm earth to the MET YUP

The main bonding should go to the MET not the earth bar in the CU ERM- That IS the Main Earthing Terminal.

Main bonding should be 10mm for it to comply to 17th AS WE`LL SEE.....

Bonding for incoming water supply should be before the T junction and within 600 mm of entering property YUP

Gas bonding should be on consumer side of meter and to 'hard' pipe not the flexible one and go to MET YUP

Do you need to bond the hot water?NO, usually. consideration should be given to whether it would introduce an earth potential and thus is it an extraneous conductive part?

Think I would point all this out to customer and give quoote for remedial work. As a minimum I would connect the existing bonding correctly to MET and pipework as it isn't safe to be left as it is

Lack of experience in inspection and testing stops me getting further into this. There appears to be other defects with wiring in cu but thats a different problem:|
You can get a 16mm in those earth bars. If the tails are 16mm I think you can leave it (I would upgrade it)Disagree, on both points.Water bond before the 'T' . Should be 10mm, but if customer refuses you can only do what you can do. Agreed

Gas should be 10mm with a earth bonding label.YUP

Quote from BS7671: 2008 "Existing installations that have been installed in accordance with earlier editions of the regulations may not comply with this ediion in every respect. This does not necessarily mean they are unsafe for continued use or require upgrading"
Doesn`t mean they`re "safe", either.

Looking at photos it looks like there is no main bond to water pipe,Though SL tells us there is.6mm main earth cable is only single colour so does not comply on size and also colour. Agreed.

Bond to gas is not to current regs and should be affixed to wall. what should?

batty
I`ve had issues with a 16mm EC into these boards. Usually end up with a Henley as my MET, unless I can get the CU upgradedPray.

Can`t just take the bond from hot pipe onto cold, as cable is supposed to be continuous. Suppose you could crimp connect the two cables, and run them through the cold water earth strap ( moved to correct position, obviously!)

If you are happy that 6mm bonds will be acceptable, and explain your reasons, that`s up to you. I`d recommend changing, but couldn`t push it unless there were substantiating test results, to suggest 6mm unsafe.

EC upgrade to 16mm - naturally.

 

steptoe

of course Im wrong, ask my wife™
Joined
Feb 13, 2008
Messages
24,422
Reaction score
160
Location
Gtr Manchester
mate - i'm a vet not a spark. I was just trying to put a point of view. I'm not trying to wind you up :)
no probs buddy,

as my sig says........

Im only me, stick around long enough and you'll learn I say what I think, not always right, just my opinion.

 

steptoe

of course Im wrong, ask my wife™
Joined
Feb 13, 2008
Messages
24,422
Reaction score
160
Location
Gtr Manchester
PUSHY SHOVEY BY STEPTOE!, AND APACHE!Not fair, guys.

Steps, mate. You stole MY idea. Grrrrrrrrr
how the **** you work that out?????

its been on here for ages, and my computer went **** up earlier, and Im just back from pub,,,,,

so stop cheating........

 
Top