Stupid Question On Bonding?

[ban-all-sheds]

Certainly the Rad would have been an issue

Why?

and bonding would have been attached to the Rad

Why?

same with the taps,

Why?

what about the metal fillings in your teeth Ban?

Indeed - what about them? That was the whole point of my examples such as the metal tumbler, and the razor handle, and the metal comb.

It's madness to have a simple rule of "if it's metal and in a bathroom you should bond it." You have to apply more thought than that.

While i agree that a higher impedance path would reduce the shock, it all seems a bit iffy that you "hope" that the impedance of an unbonded say Rad for instance is high enough not to give a fatal shock, leaving unbonded and unequipotential(if there is such a word) metalwork in a zone makes for a very uncertain installation.

Please explain the fascination with radiators. (And taps). Let's make some of my questions above non-rhetorical.

Would you bond items like these:

If not, why not? They are made of metal, and they are screwed to the wall, like radiators are.

And if you wouldn't bond those, then why bond other metal objects that are also not extraneous-conductive-parts? You don't have to hope that there's a high impedance path, you only have to look at the results of the research done - even with a double dose of inhibitor, 15mm plastic central heating pipes have a resistance of over 20kohms/m. Pure water, such as that being supplied to the taps is 115kohms/m.

Assume a worst case wet-body resistance of 250 ohms, then any impedance in a fault path of 7k5 ohms or above produces a fault current of <30mA.

At least with the "old" way you were certain of equal earth potential and the rest of the regs covered fault conditions such as adequate cpc and fusing to try to prevent a shock hazard.

But now we have new ways, of plumbing, and the old ways, of electrics, need to be changed.

Just for a moment think of ways that metalwork in a zone may become live and stay live if all the other precautions had been adhered to.

I can't think of any, other than grossly obvious ones, like cables or appliances falling off the walls, and they are not specific to bathroom zones.

To say that an unbonded piece of metalwork is high impedance without having tested it to see if that is the case leaves a lot of uncertainty who knows if the plastic pipe fed rad isn't already at or near earth potential anyway? Maybe a fixing screw has touched earthed metalwork inside the wall say for instance the metal mesh plasterers use on corners this may be in contact with a switch box? Can you see the point i'm making? better certainty than uncertainty.

NO - if you're concerned about the extraordinarily unlikely scenario you mention, then test, because if you bond an otherwise isolated radiator fed by plastic pipes then you have made things less safe, not more.

 

[kendor]

Reference to your fillings was a joke Ban , didn't think I would have to explain that but looks like i will have to make an exception in your case next time
If you read my post i said that was the "old" way(and still the best way i reckon)
Pure water! out of the tap now YOU must be joking

You say new methods of plumbing? sorry plastic was used at the time of the 15th edition regs and it was because of this that the bonding was So important as you were unable to get a decent low earth reading otherwise, perhaps you are new to the industry and don't remember the 15th edition regs?
you mention testing but that was exactly what was done to make sure it all complied with the regs not the hope for the best installation that you seem to be so akin to.

and i asked the question hoping for a decent answer but you couldn't come up with one except for your usual "i dont know the answer so i'll make a sarcastic comment" retort regarding knowing of a way that a piece of metalwork could become live and stay alive if the regs had been adhered to (this would apply whatever regs you care to quote, if the installation has been done properly, if not then even the latest regs aint gonna help you my son!).

Anyone got constructive criticism?

 

[ban-all-sheds]

Reference to your fillings was a joke Ban , didn't think I would have to explain that but looks like i will have to make an exception in your case next time

What makes you think you have to explain it? I assumed it was a joke, and that you'd made it because you recognised that in my list, items like razor handles and bathrobe hooks were meant to be joke items, designed to highlight how ludicrous it is to bond "ANY metalwork within Touch of each other".

If you read my post i said that was the "old" way(and still the best way i reckon)

You keep saying that, but so far you've not explained why.

You say new methods of plumbing? sorry plastic was used at the time of the 15th edition regs and it was because of this that the bonding was So important as you were unable to get a decent low earth reading otherwise,

I thought we were discussing supplementary equipotential bonding, not earthing.

you mention testing but that was exactly what was done to make sure it all complied with the regs not the hope for the best installation that you seem to be so akin to.

What an odd interpretation to put on a suggestion that one could test instead of hoping for the best that a fixing screw had not penetrated some earthed metalwork.

and i asked the question hoping for a decent answer but you couldn't come up with one except for your usual "i dont know the answer so i'll make a sarcastic comment" retort regarding knowing of a way that a piece of metalwork could become live and stay alive if the regs had been adhered to (this would apply whatever regs you care to quote, if the installation has been done properly, if not then even the latest regs aint gonna help you my son!).

I am beginning to wonder why I'm discussing this with you, since you are either deliberately misinterpreting what I write in order to anger or upset me, or you are not bothering to read it properly.

Q: Just for a moment think of ways that metalwork in a zone may become live and stay live if all the other precautions had been adhered to.

A: I can't think of any, other than grossly obvious ones, like cables or appliances falling off the walls, and they are not specific to bathroom zones.

In what possible way was my answer a sarcastic comment? It was a genuine reply. So I'll ask you. Can you please tell me the ways in which taps in a bathroom can become live?

Anyone got constructive criticism?

I've asked you to explain whether you would bond toothbrush holders etc, and you have not replied.

I've asked you why you bond isolated metal items, and you have not replied.

How many opportunities for you to explain the basis for your ideas do you need?

I have suggested that if you are concerned that an item might be an extraneous-conductive-part even though by all accounts it should not be, then you could test to see if it is, or is not. I don't see how that is any different to any other test which is done to verify the correctness of an installation. You test for insulation resistance, rather than hoping for the best. You test for a low R1+R2, rather than hoping for the best. You test for correct polarity, rather than hoping for the best. Etc etc. But my suggestion to test for a high resistance between an exposed metal item and earth, to verify that it is not an extraneous-conductive-part, rather than hoping for the best is..... hoping for the best, it seems.

How many more constructive suggestions do you need?

You asked me a question, to which I replied that I couldn't think of an answer.

How many more attempts at constructive dialogue do you need?

 

[kendor]

I thought i had explained myself well in my original posts but you didn't seem to interpret what i was saying?
you say unlikely? but a plumber wouldn't necessarily wonder about buried cables when he screws his Rad to the wall so the rad could become earthed and even worse especially if as you suggest the better way is to be "isolated" then live!! whats a worse scenario than that?? at least if it was bonded it woul;d hopefully not be live for long( going back to the Regs being adhered to), also there have been posts about live screws not long ago and the case where the earths came out of a socket where i explained a scenario that may happen (you need to read these posts rather than me need to type it all out again as you once said i wasted my time doing so when someone had already done it before so i leave it up to you to do so before you reply again?
Its also easy for you to add your suggestion post reply but these "suggestions" were not forthcoming before I could go back and edit a post from earlier on then say i told you so.
I explained before but here you go again, better that the metalwork is at the same potential than all floating at god knows what!
You still havn't given me a good enough reason why you shouldn't have an equipotential zone and why metalwork should float.
whereas i have given you good reasons why in previous posts so go read them!

I thought we were discussing supplementary equipotential bonding, not earthing.

?? lost me there when was i talking of earthing?

 

[ban-all-sheds]

I thought i had explained myself well in my original posts but you didn't seem to interpret what i was saying?
you say unlikely? but a plumber wouldn't necessarily wonder about buried cables when he screws his Rad to the wall so the rad could become earthed and even worse especially if as you suggest the better way is to be "isolated" then live!! whats a worse scenario than that?? at least if it was bonded it woul;d hopefully not be live for long( going back to the Regs being adhered to), also there have been posts about live screws not long ago and the case where the earths came out of a socket where i explained a scenario that may happen (you need to read these posts rather than me need to type it all out again as you once said i wasted my time doing so when someone had already done it before so i leave it up to you to do so before you reply again?

I'm afraid I can't make much sense of this, but see below**

Its also easy for you to add your suggestion post reply but these "suggestions" were not forthcoming before

NOW THAT IS A F*****G LIE! The only edit I made to that post of mine above was to wrap one of the photos onto the next line because it was making the posts too wide, causing horizontal scrolling. How dare you say that my suggestion was not forthcoming before? Just how stupid do you think we all are? How could it have not been there before when before the time of that edit you had already replied "you mention testing"! But see below**

I could go back and edit a post from earlier on then say i told you so.
I explained before but here you go again, better that the metalwork is at the same potential than all floating at god knows what!
You still havn't given me a good enough reason why you shouldn't have an equipotential zone and why metalwork should float.
whereas i have given you good reasons why in previous posts so go read them!

And you still haven't given me any reason why you should bond to robe hooks, toothbrush racks, towel rings etc. I know why you haven't, but ....

**I no longer care. I no longer wish to discuss this topic with you, as not only do you incompetently and without any attempt at rational justification regurgitate all the old superstitions about radiators and taps, but you tried to defame me by making false claims that I've gone back and changed previous posts to support my position. You are not worthy of my attention.

I'm going to stop watching this topic - you can do what you like.

 

[kendor]

Boy you get wound up don't you!
All i was saying was that i understand what you were saying but disagreed.
You mention not to bond metalwork such as "isolated" rads but what about earthed appliances in the vicinity you can get a "dangerous earth return path" with them so are you suggesting a total earth free zone?
That is the danger, some earthed some not some floating it IS very uncertain, as i said before and have to repeat again as you didn't reply.If the Regs have been adhered to properly and i mention 15th/16th editions that requested the bonding then the hazards you mention were just as "unlikely"(your word not mine) to happen.
As for you mentioning the word "unlikely" that is something an Electrician wouldn't contemplate or assume, you have to as a skilled person think of unexpected situations and deal with them accordingly otherwise you could be accused of negligence in your duty of safety towards others. This is the sort of thing you are taught when you do the training to be an electrician.

So until you have come up with a strong enough argument why you shouldn't have an equipotential zone then you won't convince me otherwise.

anyway calm down son, you are definitely the Mr Angry on this forum and a lot of your comments are either unhelpful or downright rude, you need to conduct yourself with a bit of decorum.