Supplementary Bonding - How was it wired?

[Midwest]

Alot of the properties I work in, were built when the 16th Edit ruled, most with no RCD's for bathroom lighting. Majority have evidence of supplementary bonding, clamps & earth wires on basin pipework, rads etc, or in immersion heater cupboards. However, some have no sign of that. Now I've read reg 701.415.2 & 415.2.2, so you can test for the effectivness of the earthing, but I never worked under the 16th Edit, so what should I expect to see. I've mentioned earth clamps etc, but the wiring diagrams I've seen, show bonding from cpc's to extraneous conductive parts, how do you connect a 4mm cable in a light fitting? I've also read on this forum, that the supplementary bonding should not go back to the MET, but I've seen tell tell signs of 4mm earth cables in CU? So how was it installed?

 

[Clive P]

Hi,

Back in the days of the 15/16th the norm then was to run a 6mm to the bathroom from the MET/CU and bond everything in the bathroom , lighting, pipework etc as a radial circuit. Times have changed but I personally liked the idea; and yes it was sometimes a pain in the a** to make off some of the connections.

Regards.

 

[Fin170]

Well connecting a 4mm to a lighting circuit is easy, assuming you don't use pull cords

From what I've seen the norm was not to bother but failing that just connecting everything to everything else and to take it back to the MET was just good practise

 

[guest119]

Bathrooms required equipotential bonding.
Theory being to bond together every bit of pipework coming in.
IE if the bath taps, basin taps, radiator etc were bonded together then there is no possibility of a voltage appearing between any points and hurting somebody who at that time will be at their most vulnerable, naked, wet, condensation everywhere.
Heating pipes and domestic supplies are capable of bringing in a voltage. Boiler, pump, immerser etc can develop faults.
I dont remember having to include lighting.
Lighting rules were no pendant type fitting on which condensation could run down the flex into the lampholder. Batten lampholder with a Home Office Skirt or enclosed fitting only.



Taking it back to the met is a different thing, EARTHED equipotential bonding.

Boydy

 

[Midwest]

Blimey home office skirt batternholder, I remember that, wonder where the name came from (wot was the IP rating!). I've read on here quite a few times that bringing earth cable from cu into the bathroom was big no no. Is that why all the diagrams show wired to cpc. I've seem quite a few with 4mm's back to CU though.

 

[Midwest]

Has anyone wired to or come across connecting a supplementary bonding conductor to a lighting cpc?

 

[Geoffsd]

just connecting everything to everything else and to take it back to the MET was just good practise

No, it wasn't.

 

[skydog23]

Back In The days before RCD's,everything was supplementary bonded, metal windows, doors, drainpipes, door hinges and handles even the dogs metal dog tag.
If it was metal and the was a chance it could become live it was classed as an extraneous conductive part and bonded. Lol
When it came to an airing cupboard, plumbers would say it the sparks job and sparks would say the plumber should have bonded all the pipes together. bonding had to be bonded. I even bonded my car when I parked it into the garage at night, in case it rose to a dangerous potential overnight. Lol.
Prays The Lord for RCD's Loling around the floor rolling my a## off

 

[telectrix]

now that bit about the car is totally wrong. should have had it's own TT earthing, independent of the house. :driving:

 

[Knobhead]

It’s quite simple, if it don’t move and it’s metallic, slap a f***in* big earth on it.
No extraneous earth cobblers. Metallic, it’s earthed!
Window frames were a bit extreme. But between the various versions of the regulations who can’t point to brain farts on the part of the IEE/IET over the years.

Just keep in the back of your mind, Mr Cockburn was MIET.

Hang on, so am I!

 

[Deleted member 9648]

Has anyone wired to or come across connecting a supplementary bonding conductor to a lighting cpc?

Yes,done it and seen it done,the idea was to connect extraneous CP's to conductive parts within the location...which included the lighting circuit.

 

[Midwest]

Yes,done it and seen it done,the idea was to connect extraneous CP's to conductive parts within the location...which included the lighting circuit.

That's one person so far, interested to know how your terminated the cable!

 

[SPARTYKUS]

That's one person so far, interested to know how your terminated the cable!

If you mean a normal light pendant then there is usually a fair a
sized earth terminal. 4mm will fit in it, as long as it is not deformed/mangled. Keep its cross section the way it was when it was made... A perfect circle. Then there is a slim chance you may also get the other cpc's in. If not join them together another way within the enclosure, as in a choccy block (oh no!!!!!).with a bigger hole.

not sure what you're getting at....?

 

[Midwest]

I'm going to do a job, where there's no obvious sign of supplementary bonding, i.e. on bathroom rads, pipes etc. Nothing in the cu. So I started this thread just to know where else to check, before I test pipework continuity.

 

[Des 56]

That's one person so far, interested to know how your terminated the cable!

Taking a bond to the Bathrom lighting circuit was standard,not rare practice

I have seen literally hundreds of installations where the lighting has been done this way

Many of these had a rising cable near where the bathroom pull cord was located,if the terminal was not meaty enough,then a connector block was fitted
The supplementary bonding could also be found external to the Bathroom,in a nearby cupboard etc