Earth Bonding, Copper Pipe

[JohnW2]

Missed that.

No you didn't - you posted a couple of minutes before me - 'twas I that did the 'missing' (albeit whilst I was typing)!

Kind Regards, John

 

[EFLImpudence]

I missed the 'exposed' reference.

 

[JohnW2]

I missed the 'exposed' reference.

Ah, I see - I'll agree that you were a naughty boy, then

Kind Regards, John

 

[ban-all-sheds]

I don't think what I suggest was wrong, keeping continuity along all exposed conductive parts, hardly wrong.

I've replaced a lot of my plumbing in the house with plastic speedift pipe and connections...

 

[PrenticeBoyofDerry]

For the back slappers

Those are plumbing, not electrical issues - but how are you suggesting one should join plastic pipes? One can't solder them!

Well in the absence of solvent welded jointing, I personally would not use plastic or any compression joints in an area where access is difficult or non-existent, so either locate the joints where they can be accessed or use a method that does not require compression fittings, a bit of old school proper plumbing would be required, using heat, copper, flux, solder etc...
A little like what would be done if jointing an electrical cable same type of principle.
So in summary: Either avoid joint, make joint accessible or make the good using a method that would create a joint that is less likely to fail.

 

[JohnW2]

For the back slappers ... Well in the absence of solvent welded jointing, I personally would not use plastic or any compression joints in an area where access is difficult or non-existent, so either locate the joints where they can be accessed or use a method that does not require compression fittings, a bit of old school proper plumbing would be required, using heat, copper, flux, solder etc... A little like what would be done if jointing an electrical cable same type of principle. So in summary: Either avoid joint, make joint accessible or make the good using a method that would create a joint that is less likely to fail.

This is obviously pure plumbing, and such such really has no place in this forum, and certainly has nothing to do with the topic of this thread!

In common-sense terms, I have sympathy with what you say (as you say, by analogy with electrical wiring). However, as I understand it, virtually all-plastic plumbing systems (inevitably with a lot of 'inaccessible' joints/fittings) are essentially the norm for new builds, and so are becoming increasingly prevalent. Indeed, AFAICS, the 'outlawing' of joist notching makes it all-but-impossible to run long lengths of copper pipe at right angles to joists. I also have to say that, despite all my initial scepticism, I have been incredibly impressed by what I've seen of push-fit fittings (whether to plastic or copper pipe).

If you wish to discuss this further, it would probably be appropriate for you to start a new thread in the Pluming forum. The OP's question in this thread has been 'well answered'.

Kind Regards, John

 

[AlexCarp]

Where the 17th Edition wiring regulations are followed then it is unlikely you need earth bonding any more.

The idea of bonding metal which interconnects rooms is so a fault in one room can't be transmitted to another room. For example a table lamp falling and smashing the bulb with the filaments resting against a radiator can't cause one to get a shock when touching a different radiator.

It's all part of a risk assessment as an earthed radiator touched at the same time as a faulty appliance will give more of a shock than one not earthed.

However although a meter of fresh water in a plastic pipe will isolate with a plastic connector of maybe just 10mm separation with iron laden central heating water would not.

So where underfloor plastic piping is used and only where visible is there metal pipe then no real need to earth. However when plastic fittings only are used then one would need to bridge the plastic fitting with a wire.

Any screw connection needs maintenance access yet the spiral springs used with many epoxy resin type cable joints I have never trusted.

We don't live in an ideal world so you must do your own risk assessment. There is no black and white but as I said at the start with all circuits now being RCD protected the chance of a fault in one room transmitting to another room without opening the RCD is slim.

The problem is the mixture of old and new and considering how many houses still have no earth to lights which was required back in the 1960's it will take a long time before the 2008 requirement for RCD protection is adopted in all houses.

This thread is a few months old - I have being doing some searching. Interesting. As I understand it this post confirmed.... With full RCD protection, all is need is an earth cable from the electricity meter earth point strapped to a gas or water pipe. Two points occurred to me here:

1. If you have a towel radiator in a bathroom with one of those electric summer heaters in it, in zone 2 (not near the shower) does this radiator need a bonding earth cable back to the meter? Would it need one if near the shower?

2. If the gas and water pipes from outside are both plastic, which is common in new builds, what earthing is needed at the meter?

 

[EFLImpudence]

This thread is a few months old - I have being doing some searching. Interesting. As I understand it this post confirmed.... With full RCD protection, all is need is an earth cable from the electricity meter earth point strapped to a gas or water pipe. Two points occurred to me here:

Gas AND water AND any other extraneous parts entering the premises.
Plus all disconnection times must be met.

1. If you have a towel radiator in a bathroom with one of those electric summer heaters in it, in zone 2 (not near the shower) does this radiator need a bonding earth cable back to the meter? Would it need one if near the shower?

No.

2. If the gas and water pipes from outside are both plastic, which is common in new builds, what earthing is needed at the meter?

The same unless you are certain they are not extraneous.

Does your electrician not know this either?

 

[AlexCarp]

This thread is a few months old - I have being doing some searching. Interesting. As I understand it this post confirmed.... With full RCD protection, all is need is an earth cable from the electricity meter earth point strapped to a gas or water pipe. Two points occurred to me here:

Gas AND water AND any other extraneous parts entering the premises.
Plus all disconnection times must be met.

1. If you have a towel radiator in a bathroom with one of those electric summer heaters in it, in zone 2 (not near the shower) does this radiator need a bonding earth cable back to the meter? Would it need one if near the shower?

No.

2. If the gas and water pipes from outside are both plastic, which is common in new builds, what earthing is needed at the meter?

The same unless you are certain they are not extraneous.

Does your electrician not know this either?

I am just interested in the new regs that's all. I understand that a metal gas and water pipe (if metal) must be earthed to the main earth bock. If both gas and water are plastic, which as I stated is common in new builds, then do you need to ram in an earth rod outside? The reason for these additional earth paths via gas and water pipes, is in case the main earth path is disconnected for any reason. But if no extra paths are there? What do they do?

BTW, my gas and water pipes are earthed.

 

[JohnW2]

I am just interested in the new regs that's all. I understand that a metal and and water pipe (if metal) must be earthed to the main earth bock. If both gas and water are plastic, which as I stated is common in new builds,...

I'm no plumber, but my understanding is that it is illegal to have any plastic gas pipe within a residential property. That means that even if the supply pipe is predominantly plastic,it has to change to metal for the last few feet where it enters the house.

then do you need to ram in and earth rod outside? The reason for these additional earth paths via gas and water pipes, is in case the main earth path is disconnected for any reason. But if none are there? What do they do?

You have totally misunderstood. Main bonding conductors (the cables joining incoming service pipes to your installation's Main Earthing Terminal) are nothing to do with 'providing additional earth paths'. There are there to ensure that dangerous potential differences cannot exist between metal pipes which enter your house and the 'earthing' system of your electrical installation.

Kind Regards, John

 

[EFLImpudence]

I am just interested in the new regs that's all. I understand that a metal and and water pipe (if metal) must be earthed to the main earth bock.

No. They must be bonded to the Main Earthing Terminal because they are earthed - by the Earth (planet).

If both gas and water are plastic, which as I stated is common in new builds, then do you need to ram in and earth rod outside?

No. It would be better if everything was plastic.

The reason for these additional earth paths via gas and water pipes, is in case the main earth path is disconnected for any reason.

No. They are all bonded together to equalise potential because they are all earthed.
Earthing is a necessary evil - not something to be achieved.

But if none are there? What do they do?

Then they don't do anything - which is much safer.

BTW, my gas and water pipes are earthed. icon_wink.gif

Yes, that's why they are bonded.

 

[EFLImpudence]

......

 

[AlexCarp]

JohnW2 says if the gas and water supply pipes are plastic you need a metal bit? That will not go to earth.

 

[EFLImpudence]

He was only talking about the gas.

You don't want it to go to earth.

That's why above I wrote -

2. If the gas and water pipes from outside are both plastic, which is common in new builds, what earthing is needed at the meter?

The same unless you are certain they are not extraneous.