How can you Earth Bond plastic incoming mains water pipe?

[malcolmsanford]

Fit the bond, your the electrician and you have a duty of care, and your name will go on the sheet in the one and only box of: designer, installer and tester.

I never do what I'm told to do if I'm not comfortable with it, end of.

Ive just gone on a job, ripping out 25mm bonding cables and running in new 50mm ones, I'm not sure there needed, but I'm not signing any sheets.

Must admit I have never seen non-copper bonding cables at 25mm^ is that a new install and they got it wrong.

 

[tonys]

Must admit I have never seen non-copper bonding cables at 25mm^ is that a new install and they got it wrong.

These are copper.

Non PME systems need not exceed 25mm, but this is a PME system and the run is a good 35/40 meters and I think they maybe referring on Table 54.8, but I'm not sure if the main supply cables exceed 150mm.

Now if the continuity ohms reading was exceeding 0.05, then that maybe a factor.

I'm already get ----ed off being told what to do, Ive already put so called technical people in a corner with a bit of BS7671 theory and its surprising how many older people out there are blagging their way through lol

 

[Sparky Ninja]

check out 544.1.2

Ok if this topic is going to go on and on, can we discuss what's wrong with the reg?

 

[tonys]

Its telling you to bond no matter

 

[malcolmsanford]

Ok if this topic is going to go on and on, can we discuss what's wrong with the reg?

These are copper.

Non PME systems need not exceed 25mm, but this is a PME system and the run is a good 35/40 meters and I think they maybe referring on Table 54.8, but I'm not sure if the main supply cables exceed 150mm.

Now if the continuity ohms reading was exceeding 0.05, then that maybe a factor.

I'm already get ----ed off being told what to do, Ive already put so called technical people in a corner with a bit of BS7671 theory and its surprising how many older people out there are blagging their way through lol

Ahh right there PME I though you may have had a engineer not exactly reading the BRB right.

 

[tonys]

Ahh right there PME I though you may have had a engineer not exactly reading the BRB right.

I think you may of been thinking what I started think, just as well I checked the book and said nothing lol

 

[Guest123]

The NIC have their own views on extraneous conductive parts.........


http://www.electriciansforums.net/e...ical-regulations/16558-extraneous-yes-no.html

 

[telectrix]

The answer to the question is soooooo ssssssimple. if it's copper bond it in the usual way. if it's plastic, I can supply an endless quantity of plastic zip ties, quick to fit and just clamp the insulation of the bonding conductor under the tie. better still, as it's plastic pipe, just use a bit of green/yellow sleeving as the bond. makes everything look kosher for the jobsworth building inspector.

 

[ezzzekiel]

as widdler states 544.1.2 as near as practicable or after any insulating section. which is the only reg that actually gives any real wording on the matter. but with a site manager, qs and unresponsive advice from niceic i think the area should be addressed a bit more clearly within the regs.

eitherway im fitting bonding at first available point wether it returns to plastic, copper or kryptonite and they can all go jump!

 

[telectrix]

as widdler states 544.1.2 as near as practicable or after any insulating section. which is the only reg that actually gives any real wording on the matter. but with a site manager, qs and unresponsive advice from niceic i think the area should be addressed a bit more clearly within the regs.

eitherway im fitting bonding at first available point wether it returns to plastic, copper or kryptonite and they can all go jump!

welll said. totally agree with you

 

[Des 56]

as widdler states 544.1.2 as near as practicable or after any insulating section. which is the only reg that actually gives any real wording on the matter. but with a site manager, qs and unresponsive advice from niceic i think the area should be addressed a bit more clearly within the regs.

eitherway im fitting bonding at first available point wether it returns to plastic, copper or kryptonite and they can all go jump!

Now thats what I call free thinking and good on you for that attitude

All of us who may "think" we understand the objective of the regulation, has right on our side

If that objective is made much more definitive by the regulation makers,everybidy, the pretend regulation makers, (we know who that is) and sparks everywhere should be "as one" with the interpretation of what and where to bond

It does need sorting

 

[tonys]

eitherway im fitting bonding at first available point wether it returns to plastic, copper or kryptonite and they can all go jump!

If you feel there's a reasonable possibility that the pipe in question could introduce a potential, then you have make that final decision, to bond or not to bond

Ive seen plenty of sparks run a 10mm into the cylinder cupboard, and cross every pipe to make sure.

 

[pushrod]

I use 23K Ohm, derived from a 10mA fault current.

This is the overall value i'm thinking of but when you measure it you are looking for 22kΩ as you take the human body to have a resistance of 1000Ω.


Lenny (re that link) i would not be happy with taking 6667Ω as the value for an extraneous conductor as that could allow 29mA of current to flow and a grip response (ie the person being shocked can't let go) can be exhibited at 20mA. whereas the 23kΩ figure gives 10mA to which the body response is release/jump back. Surprised that niceic put their faith in that value.

 

[ELEKTRIC]

DETERMINING IF A PART IS EXTRANEOUS OR JUST A PIECE OF METAL​

A test should be made using an Insulation Resistance Tester set on MΩ, supplying 500 Volts.
Test procedure:
Connect one test lead to the metal part and the other lead to a known earth. (MET)
If the resistance value is 0.02MΩ (20000Ω) or greater, no supplementary bonding conductor is required.
If it is less than 0.02MΩ, supplementary bonding should be carried out.
From the Ohm’s law:
I = V / R; I = 500V / 20000Ω = 0.025Amp
This shows that if the fault was on a single phase 230Volt supply the current that would flow between the conductive parts would of course be only 0.012Amp.
This current is unlikely to give a fatal shock

GN8 and GN5: if extraneous metalwork is above 22KΩ then it need not be supplementary bonded.

 

[telectrix]

only problem as i see it is, what IR testers or MFTs have that kind of accuracy at such a low value?

 

[tonys]

16th Edition citb study notes used to state 0.25 megohm, but with a visual inspection. So I suppose if you can not inspect the entire length of the metallic object, you should not rely upon the test alone?