Earthing a towel rad

[2020c]

I pulled out an old radiator in ensuite and replacing it with a towel rad. There was an earth wire connected to the old rad. I've opened up the floor to expose the pipework. It's done in Plastic under the screeded floor and coming up in copper.

I was going to come up the wall in copper again and connect to the plastic piping under the floor . Will this need earthing with the already installed earth cable. Just as I write this, I've been in many a new bathroom refits and can't remember seeing and earth wires attached to the towel rad. Maybe they are earthed inside the wall which has crossed my mind. Is this essential.

 

[EFLImpudence]

I was going to come up the wall in copper again and connect to the plastic piping under the floor . Will this need earthing with the already installed earth cable.

As you say the radiator might be earthed because of its heating element (unless Class II).

On a general note, normally radiators themselves do not need "bonding" - i.e. connecting to other metal parts to ensure they are at the same potential in the event of a fault - but the pipework might if it is in substantial contact with the ground. Obviously plastic pipe does not require this as it does not conduct electricity.

 

[SUNRAY]

Personally I'd suggest maintaining the plastic as far as the rad/rail to do away withthe earth doubt, unless of course you want chrome or polished copper.

 

[Munroast]

what was earthed to the radiator ? I don't understand why a radiator connected to the CH system would require to be earthed?

 

[SUNRAY]

what was earthed to the radiator ? I don't understand why a radiator connected to the CH system would require to be earthed?

I take it you weren't around in the 70's then?

It's more a question of equipotential bonding than earthing.

 

[winston1]

I take it you weren't around in the 70's then?

In the 70s the regs were wrong, just like they are wrong now allowing a 13a socket on a lighting circuit.

 

[SUNRAY]

In the 70s the regs were wrong, just like they are wrong now allowing a 13a socket on a lighting circuit.

Trust you to begin another of your arguments.

 

[EFLImpudence]

In the 70s the regs were wrong,

Regarding bonding, I think you will find that the regulations were virtually identical to today.

The mass-bonding fad being due to misreading the regulations much as still happens today: namely not limiting the bonding requirements to extraneous-conductive-parts.

 

[SUNRAY]

Regarding bonding, I think you will find that the regulations were virtually identical to today.

The mass-bonding fad being due to misreading the regulations much as still happens today: namely not limiting the bonding requirements to extraneous-conductive-parts.

I don'thave a 14th edition to verify the actual wording but it was most certainly interpreted as 'bond all exposed metalwork'.
At the time I did a fair bit of after hours work for a builder/small time developer. In those days the electricity board would commonly install the cutout and meter to a temporary device than come back to inspect the full installation before making the final connexion and sealing.
The builder got to the silly situation where they didn't fit room doors, kitchen cupboard doors, coat hooks in the hall and other equally mundane items until after the inspection to avoid the need to run eart wires everwhere.
The plumbers helped out by slipping soldered T's over pipes and linking them to provide an electrical bond and bonding point etc.
The chippies were brilliant at providing cable routes to window hinges and handles etc.

Yes the situation was very silly but the board would not connect unless it was done, of course some inspectors applied a little leniency but one never knew who would be attending.

 

[EFLImpudence]

I don't think any of that contradicts what I wrote. The physics clearly has not changed, therefore ...

That people had to do what a mistaken inspector or board demanded still happens today.


In another thread yesterday we were shown an article in Wiring Matters where it is stated that a bathroom extractor fan must have an isolator if there is no window - obviously just as daft.

 

[SUNRAY]

I don't think any of that contradicts what I wrote. The physics clearly has not changed, therefore ...

That people had to do what a mistaken inspector or board demanded still happens today.


In another thread yesterday we were shown an article in Wiring Matters where it is stated that a bathroom extractor fan must have an isolator if there is no window - obviously just as daft.

No I've not meant to contradict anything, simply telling what happened at that time. Whether it was being over enthusiastically enforced I know not without the book. But I recall the term 'all exposed metalwork' being constantly bandied about.

 

[ETAF]

i remember a lot of books for DIY installation back in 70's 80's , interpreting the regs for you, also explaining bonding, and having earths on metal handles, metal windows , sinks , kitchen, bathroom cross bonding , baths , anything metal basically etc etc etc
I only wired a couple of houses , but one house they did check all the bonding before the consumer unit was connected up ..... really painful to make nice looking.

 

[SUNRAY]

Regardless of anything else EP bonding was required in bathrooms back then and well into the eighties I even had to bond the internal CI soil stack which was to be boxed into the corner of the bathroomand he showed me the reg at the time.
Even the glass fibre baths metal legss had a bonding point even as late as 2010.

 

[EFLImpudence]

Regardless of anything else EP bonding was required in bathrooms back then and well into the eighties I even had to bond the internal CI soil stack which was to be boxed into the corner of the bathroomand he showed me the reg at the time.

The point is though that that regulation only applied to parts that actually were extraneous-conductive-parts.

Even the glass fibre baths metal legss had a bonding point even as late as 2010.

But you didn't have to use them if not required.

 

[ericmark]

Interesting subject, bonding and earthing, may changes were due to changes in the protective devices used.

I know with the ELCB-v there was a problem if you got parrellel earth paths as it would fail to trip, so we moved to the ELCB-c what today we call the RCD.

2008 the regulations changed, two things, the bird on the power cables does not get a shock, as no ground, same idea with shaver socket, so bonding everything is not always best practice, and second is plastic pipes break the bonding, does not even need to be a pipe, a connector is enough.

So as long as a 30 mA at 40 mS RCD is fitted, bonding can be omitted, however this means all circuits in the bathroom, including the lights.

The point today is that it has been found DC can stop some RCD's tripping, it is all well and good when the RCD is secondary protection, but with TT installations we rely on the RCD, as yet not seen an EICR code 2 issued for wrong type of RCD, the BS 7671 is not retrospective, however swapping tungsten for LED means it's not the same as when fitted, so there is a debate.