ageing rellies want a new hall ceiling light

took a look - no earth just L & N pvc sheathed multi strand cables
look original 50s? 60s to me...

current light fitting is large exposed metal base and glass globe....

What technically should I do here?

and pragmatically what would I be best doing?

Jim K

On 28/03/2013 16:06, Jim K wrote:
ageing rellies want a new hall ceiling light

took a look - no earth just L & N pvc sheathed multi strand cables
look original 50s? 60s to me...

current light fitting is large exposed metal base and glass globe....

What technically should I do here?

Depends on if it really is a class I (i.e. "must be earthed") fitting or
not... if it is, then one should either provide an earth for it, or
replace it with a class II fitting.

Now how difficult that is ,depends on if you mean the whole circuit
lacks and earth[1] or just the flex connecting the pendant to the rose
lacks an earth. If its just the flex, then that can be replaced with 3
core.

and pragmatically what would I be best doing?

Either the "right thing", or ignore it.

Right thing would range from rewiring the whole circuit, or
disconnecting from the circuit and taking an earthed feed elsewhere for
that light.

If the above is a non starter, and they really don't want to lose the
metal fitting, then see if you can at least get RCD protection for the
circuit (RCBO perhaps).


[1]
http://wiki.diyfaq.org.uk/index.php?...thout_an_Earth

--
Cheers,

John.

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I never did understand this earthing of lights though, after all everything
else these days is two core and double insulated.
Brian

--
From the Sofa of Brian Gaff Reply address is active
"John Rumm" wrote in message
o.uk...
On 28/03/2013 16:06, Jim K wrote:
ageing rellies want a new hall ceiling light

took a look - no earth just L & N pvc sheathed multi strand cables
look original 50s? 60s to me...

current light fitting is large exposed metal base and glass globe....

What technically should I do here?

Depends on if it really is a class I (i.e. "must be earthed") fitting or
not... if it is, then one should either provide an earth for it, or
replace it with a class II fitting.

Now how difficult that is ,depends on if you mean the whole circuit lacks
and earth[1] or just the flex connecting the pendant to the rose lacks an
earth. If its just the flex, then that can be replaced with 3 core.

and pragmatically what would I be best doing?

Either the "right thing", or ignore it.

Right thing would range from rewiring the whole circuit, or disconnecting
from the circuit and taking an earthed feed elsewhere for that light.

If the above is a non starter, and they really don't want to lose the
metal fitting, then see if you can at least get RCD protection for the
circuit (RCBO perhaps).


[1]
http://wiki.diyfaq.org.uk/index.php?...thout_an_Earth

--
Cheers,

John.

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| Internode Ltd - http://www.internode.co.uk |
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| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 28/03/2013 16:45, Brian Gaff wrote:

I never did understand this earthing of lights though, after all everything
else these days is two core and double insulated.

Its precisely because not everything is two core and double insulated
that it is a problem. There are plenty of Class I fittings about, as
well as quite a number of trendy metal faced light switches.



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

In message , John
Rumm writes
On 28/03/2013 16:45, Brian Gaff wrote:

I never did understand this earthing of lights though, after all everything
else these days is two core and double insulated.

Its precisely because not everything is two core and double insulated
that it is a problem. There are plenty of Class I fittings about, as
well as quite a number of trendy metal faced light switches.



If this is 50s wiring I would imagine it's wired live to the switch,
then feed/return to the light fitting.
--
bert

bert ] writes:

In message , John
Rumm writes
On 28/03/2013 16:45, Brian Gaff wrote:

I never did understand this earthing of lights though, after all everything
else these days is two core and double insulated.

Its precisely because not everything is two core and double
insulated that it is a problem. There are plenty of Class I fittings
about, as well as quite a number of trendy metal faced light
switches.



If this is 50s wiring I would imagine it's wired live to the switch,
then feed/return to the light fitting.

How is that different from 10s lighting?

Alex

--
Swish - Easy SFTP for Windows Explorer (http://www.swish-sftp.org)

On Mar 28, 4:45*pm, "Brian Gaff" wrote:
I never did understand this earthing of lights though, after all everything
else these days is two core and double insulated.
*Brian

The likeliest place to get a fatal electric shock in the home is from
a light fitting. This is/was because the cables deteriorated with the
heat and the waggling about and people got a shock and fell off the
step ladder.

The fall killing them, not the electric.

Jim K wrote:
ageing rellies want a new hall ceiling light

took a look - no earth just L & N pvc sheathed multi strand cables
look original 50s? 60s to me...

current light fitting is large exposed metal base and glass globe....

What technically should I do here?

and pragmatically what would I be best doing?

Jim K

I it is a new fitting in the existing location then I don't believe
there is any obligation to bring it up to standard.
An extra fitting is a grey area where most professionals will put the
fear of God into the customer and do a proper job - in extremis update
the whole lighting circuit.

Pragmatic solution? I think you know that one already!

On 28/03/2013 16:26, Bob Minchin wrote:
Jim K wrote:
ageing rellies want a new hall ceiling light

took a look - no earth just L & N pvc sheathed multi strand cables
look original 50s? 60s to me...

current light fitting is large exposed metal base and glass globe....

What technically should I do here?

and pragmatically what would I be best doing?

Jim K

If it is a new fitting in the existing location then I don't believe
there is any obligation to bring it up to standard.

So, if a class 1 fitting was installed in a lighting circuit without an
earth, what are the real world safety risks?

It will presumably only be touched when changing a lamp?



--
Dave - The Medway Handyman www.medwayhandyman.co.uk

On 29 Mar, 08:43, The Medway Handyman
wrote:
On 28/03/2013 16:26, Bob Minchin wrote:









Jim K wrote:
ageing rellies want a new hall ceiling light

took a look - no earth just L & N pvc sheathed multi strand cables
look original 50s? 60s to me...

current light fitting is large exposed metal base and glass globe....

What technically should I do here?

and pragmatically what would I be best doing?

Jim K

If it is a new fitting in the existing location then I don't believe
there is any obligation to bring it up to standard.

So, if a class 1 fitting was installed in a lighting circuit without an
earth, what are the real world safety risks?

It will presumably only be touched when changing a lamp?

indeed & with hopefully the switch "off"....

Cheers
Jim K

On 29/03/2013 09:06, Jim K wrote:
On 29 Mar, 08:43, The Medway Handyman
wrote:
On 28/03/2013 16:26, Bob Minchin wrote:









Jim K wrote:
ageing rellies want a new hall ceiling light

took a look - no earth just L & N pvc sheathed multi strand cables
look original 50s? 60s to me...

current light fitting is large exposed metal base and glass globe....

What technically should I do here?

and pragmatically what would I be best doing?

Jim K

If it is a new fitting in the existing location then I don't believe
there is any obligation to bring it up to standard.

So, if a class 1 fitting was installed in a lighting circuit without an
earth, what are the real world safety risks?

It will presumably only be touched when changing a lamp?

indeed & with hopefully the switch "off"....

I have been warned not to clean my fluorescent light when it's switched
on. The electrician said there was no earth and he wasn't supposed to be
fitting it.

On 29/03/2013 08:43, The Medway Handyman wrote:
On 28/03/2013 16:26, Bob Minchin wrote:
Jim K wrote:
ageing rellies want a new hall ceiling light

took a look - no earth just L & N pvc sheathed multi strand cables
look original 50s? 60s to me...

current light fitting is large exposed metal base and glass globe....

What technically should I do here?

and pragmatically what would I be best doing?

Jim K

If it is a new fitting in the existing location then I don't believe
there is any obligation to bring it up to standard.

So, if a class 1 fitting was installed in a lighting circuit without an
earth, what are the real world safety risks?

In reality, not many - but some...

This is a general problem compounded by the age of some lighting
circuits. Often they were the first to go into a house, and are probably
one of the more likely places to still find old flaky rubber insulation.

IME its not uncommon for the wires that run through the metalwork of
multi arm style luminaries to suffer insulation failure or damage over
the years anyway (often as a result of a batten holder working lose, and
rotating somewhat as the lamp is changed). So there is some risk of the
metalwork becoming live as a result. Other light fittings that are wired
and then fixed in place like wall lights, also have a reasonable chance
of pinching a wire and suffering the same problem.

If the circuit/fitting was earthed, then this would be a non issue since
the protective device would trip/blow.

With it unearthed, then it means that the person changing the lamp (or
operating the metal switch) will be exposed to a mains voltage. The risk
from this will obviously vary with he circumstances. So warm dry day, on
carpet on floorboards wearing shoes etc, you won't even feel a tingle.
Concrete floor in your bare feet, or with your leg touching a radiator,
then possibly a half day out with an undertaker.

It will presumably only be touched when changing a lamp?

Yup usually, but note the issue applies to metal faced switches as well.
Note as well that houses are getting shorter and people taller, so the
ease of doing that increases. Hopefully one would only change a lamp
with the fitting off, but as you know, that is not always obvious. Even
with it off, one hopes the functional switching is in the live and not
the neutral.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 29 Mar, 15:30, John Rumm wrote:

So, if a class 1 fitting was installed in a lighting circuit without an
earth, what are the real world safety risks?

In reality, not many - but some...

This is a general problem compounded by the age of some lighting
circuits. Often they were the first to go into a house, and are probably
one of the more likely places to still find old flaky rubber insulation.
snip

If one met this issue, say in the final 50mm of the L & N when
removing the old fitting, what's the prognosis? - rewire required or
tape up or shrink sleeve or ??

(& many thanks for the detailed walk through John)

Cheers
Jim K

On Friday, March 29, 2013 5:28:35 PM UTC, Jim K wrote:
On 29 Mar, 15:30, John Rumm wrote:

So, if a class 1 fitting was installed in a lighting circuit without an
earth, what are the real world safety risks?

shock & electrocution, but the number of deaths from lighting is near zero. There's a very long list of other risks far greater in life that we all accept daily.


If one met this issue, say in the final 50mm of the L & N when
removing the old fitting, what's the prognosis? - rewire required or
tape up or shrink sleeve or ??

Its upto you. Often its only the exposed rubber end that's perished, when the rubber cable has secondary inuslation. Then sleeving will suffice. However it would suggest that all such junctions are liable to be that bad - but if it is only the ends perished its a lunch money diy job.

If the whole run of rubber's perished, often the way when single insulated twisted wire was used, I'd remove the fuse promptly.


NT

On 29/03/2013 17:28, Jim K wrote:
On 29 Mar, 15:30, John Rumm wrote:

So, if a class 1 fitting was installed in a lighting circuit without an
earth, what are the real world safety risks?

In reality, not many - but some...

This is a general problem compounded by the age of some lighting
circuits. Often they were the first to go into a house, and are probably
one of the more likely places to still find old flaky rubber insulation.
snip

If one met this issue, say in the final 50mm of the L & N when
removing the old fitting, what's the prognosis? - rewire required or
tape up or shrink sleeve or ??

Well both probably... rubber in that state is possibly a serious fire
risk - however it does tend to fail at the ends first. Either way you
should take it as a strong indication that the circuit needs rewiring ASAP.

I would say that if the circuit passes an insulation resistance check,
then you could get away with sleeving and reconnecting - but only as a
short term fix. If the insulation fails, then disconnect it immediately.




--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Jim K wrote:
ageing rellies want a new hall ceiling light

took a look - no earth just L & N pvc sheathed multi strand cables
look original 50s? 60s to me...

current light fitting is large exposed metal base and glass globe....

What technically should I do here?

and pragmatically what would I be best doing?

Jim K
Would it be possible to lift a floorboard and run an earth cable to
somewhere?

Bill

On Thursday, March 28, 2013 4:06:12 PM UTC, Jim K wrote:
ageing rellies want a new hall ceiling light

took a look - no earth just L & N pvc sheathed multi strand cables

If cable in ok condition, just fit nonmetal light fitting or a class II metal one. No safety problem then.


NT

On 28/03/2013 16:06, Jim K wrote:
ageing rellies want a new hall ceiling light

took a look - no earth just L & N pvc sheathed multi strand cables
look original 50s? 60s to me...

current light fitting is large exposed metal base and glass globe....

What technically should I do here?

and pragmatically what would I be best doing?

Have you had a look at the rest of the wiring? It could, at worst, mean
that the whole house wiring is unsafe. No unknown in my experience.


--
Regards Peter Crosland