Is an earth circuit required on domestic lighting circuit?

[p_a_johnson]

I gather from the forum that my house is not unique in it having no earth on the lighting circuit.

If everything is working ok do I need to bother rewiring - how unsafe is it leaving the lighting circuit as is?

What sort of cost are you looking at to rewire a medium sized 3 bed semi with nothing fancy? any ideas?

Is it possible to spur the earth off into the upstairs sockets earth? Is this safe?

 

[Inspector]

You should get a proper electrical survey done - I guess a rewire is required. Budget £1000ish.

In the event of live parts coming into contact with metallic parts on your light fittings there's a problem. The circuit protective device won't open and those parts will remain live.

You shouldn't take the earth off the socket circuit for your lights.

 

[p_a_johnson]

why not?

 

[Inspector]

You'll be adding to the socket circuit earth fault path, its bad practice and not in accordance with regulation.

 

[p_a_johnson]

so without the earth (i.e. - without rewire) will the circuit breaker (is it an RCB or an MCB or something - you'll have to excuse my lack of knowledge) on the consumer unit trip out if I came into contact with a live/ switched live on the lighting circuit or would it allow supply oblivious to the fact that I was getting fried?

 

[kendor]

Fraid there is no cop out, you need to get your lighting circuits up to standard!

 

[David P]

bad news then p_a

but thought i should play the devils advocate here anyway.

the learned posts above are right - your house isnt up to standard...

current installation standard that is.
should you make an installation you would be advised to conform to it.

however as it exists and presumably was installed to standards effective at that time does that mean you should rewire?

how many of us updated all of our windows when the new standards for insulation came in a couple of years ago?

trying to bodge an earth from the mains would be an installation - and perhaps be dangerous.

as safety is what counts I assume your wiring is in good condition and has served well so far - why not wait?

 

[p_a_johnson]

Interesting ... do any of you spark boffins agree with David P - or would you all suggest rewire asap?

 

[breezer]

wait untill what----------some gets a nasty shock? i would suggest rewire

 

[p_a_johnson]

point taken!

 

[Carloss]

Not good, and yes a re-wire asap! ,
I had to re-wire my upstairs socket cct after i tested something and had no earth; i was sure i connected it up properly then i traced it back to the source..
Was horrified to find a 1.5mm2 twin n earch installed without the earth connected just chopped back to the outer insulation.

 

[securespark]

I do not necessarily advocate this, but there is a school of thought that says that if all the light fittings on the circuit are Double Insulated (Class II) ie do not require an earth connection, and the back boxes have insulated lugs (like they did when earth-free lighting was installed in the 60's) so that contact with live metal is not possible, this would be considered safe.

 

[p_a_johnson]

so secure spark ... would this be a safer semi permanent bodge while we save up for the rewire and associated decorating costs??? - f'ing nightmare!:

do as much of the simple remedial work as I can in the loft and under the upstairs floor - replacing all the 2 core circuits with 1/ 1.5mm t&e but feeding the earth as an interim into the socket earth (just to give some protection for the metal fittings).

This would leave running fresh t&e feeds from the consumer unit which I am unsure about (unless you could advise me if this is doable by a reasonably competent diy'er like myself?) and swapping cable to the majority of light switch's to a pro such as yourself when we've got funds together. - together with a periodical to check over my work

 

[skwirrel]

Yes but windows don't catch fire or give people electric shocks

bad news then p_a

but thought i should play the devils advocate here anyway.

the learned posts above are right - your house isnt up to standard...

current installation standard that is.
should you make an installation you would be advised to conform to it.

however as it exists and presumably was installed to standards effective at that time does that mean you should rewire?

how many of us updated all of our windows when the new standards for insulation came in a couple of years ago?

trying to bodge an earth from the mains would be an installation - and perhaps be dangerous.

as safety is what counts I assume your wiring is in good condition and has served well so far - why not wait?

 

[plugwash]

replaceing the cable to the cu should be pretty easy

if the cu is split load (some on main switch some on rcd) there will be two neutral bars if not there will only be one

cables go the the fuse or mcb the earth bar and the right neutral bar

haveing said that if you cu has fises and no rcd it is probally due for replacemnt anyway but you can rewire the lights first and get the cu dealt with by a pro or deal with it yourself later

if you are replaceing the cu or getting it replaced i would stringly advise getting a mk as they have a good range of breakers and have been around a very long time

normal practice seems to be to use a split cu and put everythign except lights alarms and possiblly freezers on the rcd side

mcbs clip to a rail in a modrn cu and are scrwed to fingers from a busbar cables connect to the mcb the relavent neutral bar and the earth bar the incomeing tails go to the top of the main isolator. remeber to pull the service fuse before the meter before disocnnecting the old cu you will often need to replace the tails fomr the meter to the cu to make them reach the incomer in the new cu if this is the case then use 25mm double insulated meter tail