is supplementary bonding ever done to regs

[panny300]

can someone please explain the above. i have looked at the official diagrams that have been pointed to on this site.
i understand that all the pipework in the bathroom has to be bonded together,but i don't get the parts about any electrical items,ie lights ,showers heaters, radiators etc, i have moved 5 times and replaced lights in the bathroooms as well as for family and have never seen a 4mm wire running from them to pipework?even on new houses? (and not all of them were in zone 3 ,if that makes a difference) i have removed heaters twice and same thing no bonding,also in the past had electric showers replaced,not bonded.
i also have looked at all my families radiators as well as my own and none are bonded, are they all wrongly done?
so can someone explain the dummies version.

 

[ayen]

yes is the the answer well its is on my jobs anyway. I have never seen the point of it myself and thankfully when the latest regs update gets released in jan it will no longer need to be done. Instead all circuits in the bathroom must be covered by RCD.

 

[Spark123]

The other point to not is the 4mm² (if correct) cable does not need to go to the actual appliance, it needs to go to the CPC (earth) of each circuit supplying class 1 or 2 equipment within the zones, this means once the a circuit is supplementary bonded, the same circuit does not generally need to be supplementary bonded again. An example can be if the lighting circuit is supplementary bonded to the light switch then the rest of the lights need not be also bonded. (It should also be verified that the bonding continuity is less than 0.05 ohms between all ECPs).

 

[ELZ4742]

so whats the score on properties that are not rcd protected after the new reg is enforced?

 

[panny300]

thanks for the replies,but still a bit confused.
do you mean spark "lighting circuit is supplementary bonded to the light switch" is a bond can be run from pipework to the lightswitch?.that can't be easy? (what is ECPs)
if a bathroom is completely tiled how do you bond to say a wall heater,how do you get from the pipes under the bath to a lighting circuit?
as my original post why have i never seen any bonding to lights, heaters,radiators,
sorry for the questions but when i have a bee in my bonnet i can't give up until i understand it fully.

 

[dingbat]

Exposedconductive parts are parts of the electrical installation - light fittings, metal enclosures, switchplates, etc
Extraneous conductive parts have nothing to do with the eklectrics but may introduce an earth path - metal pipework in particular.

If you connect together these two types of conductive parts together then, in the event of a fault, the exposed and extraneous conductive parts will have the same fault voltage, so no potential difference exists between them and hence no current will flow through you if you happen to be in contact with both.

That's why.

How? Well, in addition to the 4 sq mm green-and-yellow conductor you may also use circuit protective conductors and metallic pipework as part of your supplementary bonding.

So, you only need to connect one point of any circuit in the bathroom to one point of any other circuit/s to bond the exposed conductive parts together. (E.g if the light, fan and shaver point are on ther same circuit they are already bonded by the circuit protective conductor of that circuit. If you then add a link between, say, the shower switch and the lightswitch that's it. The only awkward one is usually the electric towel rail.)

As for the extraneous stuff, if you measure less than 0.05 ohms between any points - pipes, taps, radiators, etc, then they are also already bonded. You may need to add the odd link, hot to cold, or whatever, but measure first.

All that remains then is to connect together the exposed and extraneous bits and often an easy link exists in an adjacent airing cupboard.

Measure again. If less than 0.05 ohms is measured between any of the parts in question you have achieved the objective. You are now fully protected against the event of you getting a shock under fault conditions whilst naked and wet... unless, of course, you touch an intentionally live part, while undertaking naked, wet, live electrical installation work.

To add my dissenting voice, I also think it is a complete waste of time. All you should have to do is insist that all bathroom electrical accessories are Class II.

 

[davelx]

thanks for the replies,but still a bit confused.
do you mean spark "lighting circuit is supplementary bonded to the light switch" is a bond can be run from pipework to the lightswitch?.that can't be easy? (what is ECPs)
if a bathroom is completely tiled how do you bond to say a wall heater,how do you get from the pipes under the bath to a lighting circuit?
as my original post why have i never seen any bonding to lights, heaters,radiators,
sorry for the questions but when i have a bee in my bonnet i can't give up until i understand it fully.

Well, having just finished the supplementary bonding in my bathroom - the bonding conductor goes up into the roof from under the bath following the same route as the pipes feeding the cold water tank, which are boxed in and tiles over. All I had to do was remove a tile next to the ceiling and cut a small access (Fein Multimaster is a wonderful tool), then I could push the cable down to the void under the bath, and up into the loft, where it connects to the CPC of the lighting circuit at the same JB that feeds the shaver socket and bathroom light.

Then I part lifted the floor, raised one board and ran a cable from under the bath to the CH pipes on the other side.

 

[JohnD]

If the pipes are copper, with permanent (soldered) joints, you could have used them as part of the bonding circuit, with no need to poke wires up beside them.

 

[davelx]

If the pipes are copper, with permanent (soldered) joints, you could have used them as part of the bonding circuit, with no need to poke wires up beside them.

Yes, I know, I've done that on other section where I can visually confirm that there are no compression joints. But I can't see the pipes to the loft, or reach them in the loft as they run up between the tank and the wall with only a 2-3 inch gap, tight under the sloping roof - no room to get in to fit a clamp, and they are buried in nasty itchy insulation.

So it was easier to run the cable, which I could just push through until it popped out where I could reach it.

 

[panny300]

thanks to everybody who replied, now to find something else to question

 

[Ejaz]

forgive my ignorance but how does all this work with plastic piping? my house has been re-piped with plastic piping under floor boards and copper where exposed e.g. to radiators. So the only metal in bathroom will be the radiator and the taps!

 

[sm1thson]

ejaz, (note you should have started a new topic, or even better searched and found the answer)

basically supplementary bonding is for when metal parts come into the bathroom from elsewhere, so plastic pipes coming into to bathroom connected to short metal pipes and radiators etc don’t need bonding (the pipes or the rads). There are plenty of documents to support this if you search you will fing them.

 

[Ejaz]

fanks sm1thson, i'm not normally a hijacker of threads!! i did have a search around though:

http://www.iee.org/Publish/WireRegs...tumn_plastic_pipes_to_bond_or_not_to_bond.pdf

just to clarify my shaver unit and downlights will have to be bonded?

 

[Steve]

just to clarify my shaver unit and downlights will have to be bonded?

Both need to be bonded if they are on seperate circuits. If, however, the socket is on the lighting circuit, the socket doesn't need bonding if the lights are. Similarly, the lights dont need bonding if the socket is.

 

[Spark123]

just to clarify my shaver unit and downlights will have to be bonded?

What voltage are the downlights? If they are SELV they do not require bonding. Do you have an electric shower?