Scope of wiring regs SELV
 

If I install extra-low voltage wiring, such as bell wire, ethernet, transducer
wiring, 12V power supplies for radios or similar, am I obliged to follow the
latest wiring regs, specifically about metal clips to stop the wire getting in
the way if its supports melt?

If this is out of scope of the regs, does it come into scope if a) it is done
as part of a mains wiring installation or b) it is done by a qualified
electrician?


--
Roger Hayter

Scope of wiring regs SELV
 

In article , Roger Hayter
wrote:
If I install extra-low voltage wiring, such as bell wire, ethernet,
transducer wiring, 12V power supplies for radios or similar, am I obliged
to follow the latest wiring regs, specifically about metal clips to stop
the wire getting in the way if its supports melt?

If this is out of scope of the regs, does it come into scope if a) it is
done as part of a mains wiring installation or b) it is done by a
qualified electrician?

The reason for metal clips is that a fireman got trapped and killed because
he got tangled in falling cabes. Low voltage cables are just as likely to
do this as mains ones.

--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle

Scope of wiring regs SELV
 

My common sense approach is that if it is carrying high current, or is able
to then yes, if its not ie aerials network cables etc, then no.
It always needs thicker wire for low voltage in any case, since the voltage
drop will be very big otherwise. I remember an experiment. I ran a car radio
on a 12v supply and put a bulb on the supply at the radio end. If I used a
photo transistor amplified and looked at the bulb you could not hear a thing
on a short lead, but even just 1metre of cable was enough to allow you to
hear distorted sound coming from the bulb.
Brian

--
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This newsgroup posting comes to you directly from...
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Note this Signature is meaningless.!
"Roger Hayter" wrote in message
...
If I install extra-low voltage wiring, such as bell wire, ethernet,
transducer
wiring, 12V power supplies for radios or similar, am I obliged to follow
the
latest wiring regs, specifically about metal clips to stop the wire
getting in
the way if its supports melt?

If this is out of scope of the regs, does it come into scope if a) it is
done
as part of a mains wiring installation or b) it is done by a qualified
electrician?


--
Roger Hayter

Scope of wiring regs SELV
 

On 9 Oct 2020 at 11:08:29 BST, "charles" wrote:

In article , Roger Hayter
wrote:
If I install extra-low voltage wiring, such as bell wire, ethernet,
transducer wiring, 12V power supplies for radios or similar, am I obliged
to follow the latest wiring regs, specifically about metal clips to stop
the wire getting in the way if its supports melt?

If this is out of scope of the regs, does it come into scope if a) it is
done as part of a mains wiring installation or b) it is done by a
qualified electrician?

The reason for metal clips is that a fireman got trapped and killed because
he got tangled in falling cabes. Low voltage cables are just as likely to
do this as mains ones.

Absolutely agree. I was just asking whether the regs legally applied.

--
Roger Hayter

Scope of wiring regs SELV
 

On 09/10/2020 10:48, Roger Hayter wrote:
If I install extra-low voltage wiring, such as bell wire, ethernet, transducer
wiring, 12V power supplies for radios or similar, am I obliged to follow the
latest wiring regs, specifically about metal clips to stop the wire getting in
the way if its supports melt?

If this is out of scope of the regs, does it come into scope if a) it is done
as part of a mains wiring installation or b) it is done by a qualified
electrician?


It's covered by BS7671 as the requirement there applies to "wiring
systems" which means any "assembly made up of cable or bus bars and
parts which secure and, if necessary, enclose the cable or busbars."

Whether you or anyone else is required by law to follow the regs is a
separate and more complex question. OTOH it's not on the face of it
within the building regulations so "they can't touch you for it". OTOH
if you don't use fire-resistant clips and someone dies or is seriously
injured as a result I'd hope (very possibly in vain) legal action wd
follow that at least left you very much poorer. Bear in mind the
internet has a long memory so you might after this thread struggle to
argue "innocent error".

--
Robin
reply-to address is (intended to be) valid

Scope of wiring regs SELV
 

On 9 Oct 2020 at 13:33:14 BST, "Robin" wrote:

On 09/10/2020 10:48, Roger Hayter wrote:
If I install extra-low voltage wiring, such as bell wire, ethernet,
transducer
wiring, 12V power supplies for radios or similar, am I obliged to follow the
latest wiring regs, specifically about metal clips to stop the wire getting
in
the way if its supports melt?

If this is out of scope of the regs, does it come into scope if a) it is
done
as part of a mains wiring installation or b) it is done by a qualified
electrician?


It's covered by BS7671 as the requirement there applies to "wiring
systems" which means any "assembly made up of cable or bus bars and
parts which secure and, if necessary, enclose the cable or busbars."

Whether you or anyone else is required by law to follow the regs is a
separate and more complex question. OTOH it's not on the face of it
within the building regulations so "they can't touch you for it". OTOH
if you don't use fire-resistant clips and someone dies or is seriously
injured as a result I'd hope (very possibly in vain) legal action wd
follow that at least left you very much poorer. Bear in mind the
internet has a long memory so you might after this thread struggle to
argue "innocent error".

In real life I would worry more about wires that crossed doorways or ceiling
than those along walls. But I am impressed that advice on this hasn't
filtered through to networking instructions as opposed to the actual wiring
regulations. As a matter of interest, I wonder if wires running along
plasterboard or clipped to it with metal clips meet the regulations?
Plasterboard is supposed to be somewhat fire resistant but existing
installations may not always be thick enough to count.

--
Roger Hayter

Scope of wiring regs SELV
 

On 09/10/2020 13:47, Roger Hayter wrote:
On 9 Oct 2020 at 13:33:14 BST, "Robin" wrote:

On 09/10/2020 10:48, Roger Hayter wrote:
If I install extra-low voltage wiring, such as bell wire, ethernet,
transducer
wiring, 12V power supplies for radios or similar, am I obliged to follow the
latest wiring regs, specifically about metal clips to stop the wire getting
in
the way if its supports melt?

If this is out of scope of the regs, does it come into scope if a) it is
done
as part of a mains wiring installation or b) it is done by a qualified
electrician?


It's covered by BS7671 as the requirement there applies to "wiring
systems" which means any "assembly made up of cable or bus bars and
parts which secure and, if necessary, enclose the cable or busbars."

Whether you or anyone else is required by law to follow the regs is a
separate and more complex question. OTOH it's not on the face of it
within the building regulations so "they can't touch you for it". OTOH
if you don't use fire-resistant clips and someone dies or is seriously
injured as a result I'd hope (very possibly in vain) legal action wd
follow that at least left you very much poorer. Bear in mind the
internet has a long memory so you might after this thread struggle to
argue "innocent error".

In real life I would worry more about wires that crossed doorways or ceiling
than those along walls. But I am impressed that advice on this hasn't
filtered through to networking instructions as opposed to the actual wiring
regulations. As a matter of interest, I wonder if wires running along
plasterboard or clipped to it with metal clips meet the regulations?
Plasterboard is supposed to be somewhat fire resistant but existing
installations may not always be thick enough to count.

The regs only require you to prevent /premature/ collapse of the wiring
system. I don't think it's /premature/ if the wiring comes down 'cos
the wall to which it's fixed comes down.

--
Robin
reply-to address is (intended to be) valid

Scope of wiring regs SELV
 

On Fri, 09 Oct 2020 11:08:29 +0100, charles wrote:

The reason for metal clips is that a fireman got trapped and killed
because he got tangled in falling cabes. Low voltage cables are just as
likely to do this as mains ones.

But some what easier to break than 2.5 T&E (or bigger) after a fire
has destroyed a plastic clip, which would also have annealed the
copper and removed all the insulation. Nasty all the same.

So I take it that the hardened pin and plastic cable clip fixings are
no longer legal?

--
Cheers
Dave.

Scope of wiring regs SELV
 

In article l.net,
Dave Liquorice wrote:
On Fri, 09 Oct 2020 11:08:29 +0100, charles wrote:

The reason for metal clips is that a fireman got trapped and killed
because he got tangled in falling cabes. Low voltage cables are just as
likely to do this as mains ones.

But some what easier to break than 2.5 T&E (or bigger) after a fire
has destroyed a plastic clip, which would also have annealed the
copper and removed all the insulation. Nasty all the same.

the size of copper depends on the current carrying capacity, not the
insulation.


So I take it that the hardened pin and plastic cable clip fixings are
no longer legal?

depends where

--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle

Scope of wiring regs SELV
 

On Fri, 09 Oct 2020 18:19:13 +0100, charles wrote:

But some what easier to break than 2.5 T&E (or bigger) after a
fire
has destroyed a plastic clip, which would also have annealed the
copper and removed all the insulation.

the size of copper depends on the current carrying capacity, not the
insulation.

For a Cat5 cable the insulation makes up most of the cables tensile
strength.

So I take it that the hardened pin and plastic cable clip fixings
are
no longer legal?

depends where

Expand?

--
Cheers
Dave.

Scope of wiring regs SELV
 

On 09/10/2020 13:03, Roger Hayter wrote:
On 9 Oct 2020 at 11:08:29 BST, "charles" wrote:

In article , Roger Hayter
wrote:
If I install extra-low voltage wiring, such as bell wire, ethernet,
transducer wiring, 12V power supplies for radios or similar, am I obliged
to follow the latest wiring regs, specifically about metal clips to stop
the wire getting in the way if its supports melt?

If this is out of scope of the regs, does it come into scope if a) it is
done as part of a mains wiring installation or b) it is done by a
qualified electrician?

The reason for metal clips is that a fireman got trapped and killed because
he got tangled in falling cabes. Low voltage cables are just as likely to
do this as mains ones.

Absolutely agree. I was just asking whether the regs legally applied.


Not if you stick them under the carpet or round the perimeter in
trunking :-)