Shurely this has never been standard practice

[MrTinker]

Recently went to my uncles bungalow to sort out a burst water pipe in the loft and check over the electrics for water damage. up in the loft theres a junction box thats had a right soaking so thought best have a look in there, took the top off and just went WHAT simple setup 3 twin&earth cables supply in supply out and one to kitchen light(god knows why the switch cable ain't in there) thing is on the 2 supply cables the earths have been cut off flush with where the outer has been striped back to, and on the branch cable going to the light, the earth is about 2ft long and taped to a cold water pipe! anyone else seen anything like that before?

 

[ColJack]

my guess is that it's a new part to an old install..
no earth in the old so they cut it out of the new..
then someone altered it and thought that it needs an earth ( metal fitting is it? ), hence the bodge to the water pipe ( which should be bonded back to the MET? )

 

[ericmark]

I think around 1964 the rules on earths and lights changed. From that point lights have been earthed but before that it was common not to earth lights.

In a way one can see the reason the normal ceiling rose even today terminates into a twin core flex to the double insulated BA22d bulb socket so why bother with earth?

Well reason is three fold. One we do use light fittings with metal and unless there is an earth then we can't use these fittings this includes using a florescent fitting in kitchen. Second with no earth can't use metal light switches. Third is where the cable is cut through there is no earth to open protective device.

However the Electrical Safety Council still sanctions just putting stickers on the consumer unit and using all class II lamp fittings and switches.

I have in the past tried to reconnect the earths and have failed because one junction box can't be found. Rules say earth cable must follow same root as live cables and if not as part of same cable or in same conduit then min of 4mm so in real terms just as easy to renew whole cable as to add an earth.

As to water pipe and earths normally a special clip is used which also has a do not disconnect notice. But with plastic fittings and pipe the whole idea of ensuring pipes are earthed becomes hard. But today with the use of 30ma at 40ms RCD's on all circuits the problem of shocks being passed thought out the house vie the pipework is being tattled in a different way. Of course some old houses don't have a RCD fitted on every circuit so still need careful attention to be paid to bonding but it all depends on the version of BS7671 that the electrics in the house complies with.

 

[MrTinker]

Thanks for the replys. It is a florescent in the kitchen so i see why the atempt to earth it, the house was built in the early 60's so makes sense, i didn't realise the earthing regs where changed then i thought it was much earlier(you learn something new every day)
My sugestion of replacing the fuse box with a RCD cu and re-wiring the lighting, has been over ruled at the moment due to cost, the florescent needs changing so i think a couple of standard fittings in it's place should solve any earthing problems for now.
Thanks again for the info

 

[ColJack]

or as it's a bungalow it shouldn't be that hard to run an 1.5mm earth back to the CU from the lights that need it..

 

[ban-all-sheds]

the florescent needs changing

 

[tonyelectric]

The earthing attempt may well have had more to do with function than safety, fluorecent lights require the metalwork to be earthed in order to aid the tube starting as much as they need it for safety.

 

[Adam_151]

The earthing attempt may well have had more to do with function than safety, fluorecent lights require the metalwork to be earthed in order to aid the tube starting as much as they need it for safety.

I've heard that a few times, but I've come across quite a few that have had open circuit cpcs, and none seemed to have any trouble starting

 

[crystal ball]

The earthing attempt may well have had more to do with function than safety, fluorecent lights require the metalwork to be earthed in order to aid the tube starting as much as they need it for safety.

I've heard that a few times, but I've come across quite a few that have had open circuit cpcs, and none seemed to have any trouble starting

Me too, seen plenty of unearthed fluoros in my time, they all seem to fire up ok, any further info tony

 

[mattylad]

Some may seem to fire up OK but in general the circuits does work better if there is a ground reference for the tube.
Not all fittings require it.

 

[securespark]

I've experienced a couple of RING flu's that start easier when connected to a sound earth.

Eric, AFAICT, cpcs in lighting (and for that matter PEB's) came in with the 14th Ed. in 1966.

Or are you right? Were the above added in the amendment to the 13th in 1964??

Anyone got a copy of the 13th Ed?

 

[Paul_C]

It was the 14th edition in 1966 which introduced the requirement to provide an earth at every light fitting and switch:

D.6 At every lighting point an earthing terminal shall be provided and connected to the earth-continuity conductor of the final sub-circuit.

D.7 An earthing terminal, connected to the earth-continuity conductor of the final sub-circuit, shall be provided at every lighting switch position unless this takes the form of an earthed metal box having a means of fixing the switch-plate in reliable electrical contact with the box.

NOTE. - Regulations D.6 and D.7 are applicable even where a point or switch position is intended, at the time of installation, for the attachment of an all-insulated accessory or fitting or a double-insulated fitting. They are intended to allow for any later substitution of an accessory or fitting which needs to be earthed.

However, contrary to what seems to be popular belief, there was no blanket exemption from providing earths on lighting circuits under the 13th edition. The relevant exemption can be found in regulation 403 (ix):

Lighting fittings using filament lamps installed in a room having a non-conducting floor, mounted at such a height that they cannot readily be touched and are out of reach of earthed metal.

Note that this applies only to filament lamps, so the metal casing of a fluorescent light fitting still needed to be earthed under the 13th edition, as did other types of discharge lamps, metal switch plates, and so on.

 

[bernardgreen]

Lighting fittings using filament lamps installed in a room having a non-conducting floor, mounted at such a height that they cannot readily be touched and are out of reach of earthed metal.

Note that this applies only to filament lamps, so the metal casing of a fluorescent light fitting still needed to be earthed under the 13th edition, as did other types of discharge lamps, metal switch plates, and so on.

Based on that what has to happen if the lamp in an acceptably un-earthed fitting is replaced by a non filament lamp. An energy saving lamp for example.

 

[tonyelectric]

I don't think thats a problem as CFLs are double insulated construction and do not have a functional earth.

I'm 99% sure the reason that earthing was required to florrys was as much to comply to makers specs as for safety reasons back then. I agree with those who say that florrys generaly fire up OK without earth, but bear in mind back then the earth strip tube was common place and those really don't work well without an earth

 

[bernardgreen]

I agree it is not a problem but I wonder if some "jobs worth" will spot it and insist that earths are installed before energy saving lamps can be used.

CFLs are double insulated construction

Dubious

One make had bayonet pins that were the ends of a bar that went right across the inside of the lamp. The thinly insulated wires to the contact pads were touching the bar. Had that insulation failed ( or melted ) with the lamp in a metal fitting the fitting could have become live. That make is no longer imported