I understand that the only changes to the latest 17th amendment CUs is the addition of SPDs, however I believe there are exceptions to the rule depending on the type of property and the number of occupants. So would a two bedroom bungalow with two occupants fall into the exception category?

In the garage I am using PVC trunking to run cables round and to comply with the latest fire rating requirements I am using some metal inserts that support the cables. The problem with the cable clips is that they do not match the trunking perfectly requiring a slight modification to the trunking to get them to fit. This is dragging out the job a bit and I am looking into alternatives. What I am looking for is a recommended spacing within the trunking for whatever type of fire clips I use, surely it cannot be the same as the recommended spacing of the old plastic cable clips?

Richard

On Thursday, 18 July 2019 23:29:53 UTC+1, Tricky Dicky wrote:
In the garage I am using PVC trunking ...

The fire retaining cable clips do not have to be within the trunking.

Builder's perforated band round the outside of the trunking will support the cables (and trunking) in the event of a fire.

Spacing has to be sufficient to stop the cables becoming an entanglement hazard. Along a wall every 1m or 1.5m may be sufficient, and each side of a doorway (more over a garage vehicular door).

Owain

On 18/07/2019 23:29, Tricky Dicky wrote:
I understand that the only changes to the latest 17th amendment CUs is the addition of SPDs, however I believe there are exceptions to the rule depending on the type of property and the number of occupants. So would a two bedroom bungalow with two occupants fall into the exception category?

With luck someone who really knows will be along i.d.c. with a simple,
reassuring answer.

In the meantime...while looking at a new CU here I depressed myself by
looking at Appendix B to the BEAMA guide (link below) which sets out
what's involved in deciding if an SPD is needed. I was lucky. It has
an example which fits here to a T with the answer "not a requirement".
Be warned though, Appendix B seriously confirmed my belief that the regs
are getting beyond the capacity of the average sparks.

There is (assuming you don't have an overhead supply) an exception for
"for single dwelling units where the total value of the installation
and equipment therein does not justify such protection and the
consequential losses are tolerable." But that seems to me a bit of a
minefield when it "is further explained in IEC 60364-4-44 which states
that overvoltage protection is not required for single dwelling units
where the total economic value of the electrical installation to be
protected is less than five times the economic value of the SPD located
at the origin of the installation". I suspect rather few homes don't
have a TV, PVR, washing machine, etc at risk from a surge worth more
than 5 times the cost of an SPD.

And I was also left wondering how insurance companies would deal with on
a claim for losses due to a power surge if no SPD was fitted post-18th.
Want to see a risk assessment from a pro before paying out?


http://www.beama.org.uk/asset/186E3B...9624295252303/

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

On 18/07/2019 23:29, Tricky Dicky wrote:

I understand that the only changes to the latest 17th amendment CUs
is the addition of SPDs, however I believe there are exceptions to
the rule depending on the type of property and the number of
occupants. So would a two bedroom bungalow with two occupants fall
into the exception category?

For domestic its down to the owner to decide if its worth having.

In the garage I am using PVC trunking to run cables round and to
comply with the latest fire rating requirements I am using some metal
inserts that support the cables. The problem with the cable clips is
that they do not match the trunking perfectly requiring a slight
modification to the trunking to get them to fit. This is dragging out
the job a bit and I am looking into alternatives. What I am looking
for is a recommended spacing within the trunking for whatever type of
fire clips I use, surely it cannot be the same as the recommended
spacing of the old plastic cable clips?

No, you can go wider on the clips. There seems to be no official
guidance, but common sense would suggest at least every 1.5m in general
cases and a bit closer over access routes.

--
Cheers,

John.

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

On Friday, 19 July 2019 11:00:19 UTC+1, Robin wrote:
I suspect rather few homes don't have a TV, PVR, washing machine,
etc at risk from a surge worth more than 5 times the cost of an SPD.
And I was also left wondering how insurance companies would deal with on
a claim for losses due to a power surge if no SPD was fitted post-18th.
Want to see a risk assessment from a pro before paying out?

Unless it's a term of the insurance policy I don't think they could refuse.

The DNOs on the other hand might well limit their payout after a surge to the five times limit on the grounds that anything else is now up to the consumer to protect against.

Owain

Looks like an SPD will be fitted purely on the principle that we have electronic equipment whose value easily outweighs the cost of even the most costly SPD I have come across so far and what cost do you put on a human life?

As for the fire safety clips I have very little surface wiring but I take it from replies so far that I can use standard plastic clips interspersed with metal clips at intervals between 1m and 1.5m. I have been using those expensive Thorsman ones Screwfix sell and find them unsatisfactory in that they do not grip the cables tight enough which slide through them quite easily the result is you cannot get the tension on the cable to produce nice straight runs.

As far as the trunking is concerned at present I have 12m installed so at a spacing of 1m I am only talking at about 12 or thereabouts. I might look at using builders band on the outside of the trunking still looking at the possibilities. Most of the available solutions do not seem to be designed to grip cables firmly but more provide loose support for the cables.

Thanks for the advice so far, I am still open to any more suggestions.

Richard

On 19/07/2019 20:53, Tricky Dicky wrote:
Looks like an SPD will be fitted purely on the principle that we have
electronic equipment whose value easily outweighs the cost of even
the most costly SPD I have come across so far and what cost do you
put on a human life?


That sounds as false as insisting on windmills on the basis that they
MIGHT save CO2 emissions and those MIGHT be implicated in unpleasant
climate change.

In my increasingly long life I have only ever seen surge damage in the
case of near (or direct) lightning strike.

And I cant recall ANY of the damage being via the mains. Mains already
had RF filters : Mains transformers won't propagate fast edged spikes
and SMPSUS have ****ing great caps to absorb it

In short surge protection is about as pointless as Russ Andrews $45000
hifi cables.

--
Outside of a dog, a book is a man's best friend. Inside of a dog it's
too dark to read.

Groucho Marx

On Saturday, 20 July 2019 05:16:07 UTC+1, The Natural Philosopher wrote:
On 19/07/2019 20:53, Tricky Dicky wrote:
Looks like an SPD will be fitted purely on the principle that we have
electronic equipment whose value easily outweighs the cost of even
the most costly SPD I have come across so far and what cost do you
put on a human life?


That sounds as false as insisting on windmills on the basis that they
MIGHT save CO2 emissions and those MIGHT be implicated in unpleasant
climate change.

In my increasingly long life I have only ever seen surge damage in the
case of near (or direct) lightning strike.

And I cant recall ANY of the damage being via the mains. Mains already
had RF filters : Mains transformers won't propagate fast edged spikes
and SMPSUS have ****ing great caps to absorb it

In short surge protection is about as pointless as Russ Andrews $45000
hifi cables.

It has 2 points
1. to take your money
2. to catch fire


NT

On 19/07/2019 20:53, Tricky Dicky wrote:
Looks like an SPD will be fitted purely on the principle that we have electronic equipment whose value easily outweighs the cost of even the most costly SPD I have come across so far

but you also have to factor in the risk of a power surge causing harm.
I've only lost 2 bits of kit in 30-odd years: a PVR and an ATX power supply.

and what cost do you put on a human life?


That's been a routine job in cost-benefit appraisal for decades. But
it's true that many would disagree with eg NICE's use of about £30,000
for a year of good quality life - especially when it's their life

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

but you also have to factor in the risk of a power surge causing harm.
I've only lost 2 bits of kit in 30-odd years: a PVR and an ATX power supply.

The risks of power surges seems quite low, to my knowledge I have never experienced one certainly not one that has resulted in damage or injury. It seems that the IET is getting to the point of trying to eliminate any risk no matter how small. To be honest it seems more faff to do the CRL calculation and the risk assessment than to stomp up the money and the few minutes to fit the device.

Richard

Tricky Dicky wrote:

The risks of power surges seems quite low, to my knowledge I have
never experienced one certainly not one that has resulted in damage
or injury. It seems that the IET is getting to the point of trying to
eliminate any risk no matter how small. To be honest it seems more
faff to do the CRL calculation and the risk assessment than to stomp
up the money and the few minutes to fit the device.

Quite a lot of the youtube sparkies seem to fit Hager CUs, and recently
they seem to be fitting SPD versions (sponsored?) though some of them
say if the customer doesn't want to pay, they get a disclaimer from the
customer and don't bother.

I had a look at the Hager brochure, which shows 20 and 40 way CUs
brimming with SPDs, RCCBs and AFDDs (and incidentally shows quite sloppy
amounts of copper poking out of terminals)

https://www.hager.co.uk/files/download/0/373205_1/0/HAGER-RESIDENTIAL-CATALOGUE.PDF

£90 quid for replacement SPD cartridges? hmm. £90 per AFDD that AFAIR
john ward couldn't force to trip on very obvious arcs? hmm.

On 20/07/2019 12:25, Andy Burns wrote:
Tricky Dicky wrote:

The risks of power surges seems quite low, to my knowledge I have
never experienced one certainly not one that has resulted in damage
or injury. It seems that the IET is getting to the point of trying to
eliminate any risk no matter how small. To be honest it seems more
faff to do the CRL calculation and the risk assessment than to stomp
up the money and the few minutes to fit the device.

Quite a lot of the youtube sparkies seem to fit Hager CUs, and recently
they seem to be fitting SPD versions (sponsored?) though some of them
say if the customer doesn't want to pay, they get a disclaimer from the
customer and don't bother.

I had a look at the Hager brochure, which shows 20 and 40 way CUs
brimming with SPDs, RCCBs and AFDDs (and incidentally shows quite sloppy
amounts of copper poking out of terminals)

https://www.hager.co.uk/files/download/0/373205_1/0/HAGER-RESIDENTIAL-CATALOGUE.PDF


£90 quid for replacement SPD cartridges? hmm.Â* £90 per AFDD that AFAIR
john ward couldn't force to trip on very obvious arcs? hmm.


Guess how many I have fitted on a domestic property?

--
Adam

S.f.a I should think!

On 20/07/2019 14:31, wrote:
S.f.a I should think!


Indeed. But Adam /is/ based in S. Yorkshire where they





















































don't get much lightning compared with some other places.

There's even less lightning in mist of Scotland - but of course
correlation doesn't imply causation


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

On 20/07/2019 10:15, Robin wrote:
On 19/07/2019 20:53, Tricky Dicky wrote:
Looks like an SPD will be fitted purely on the principle that we have
electronic equipment whose value easily outweighs the cost of even the
most costly SPD I have come across so far

but you also have to factor in the risk of a power surge causing harm.
I've only lost 2 bits of kit in 30-odd years: a PVR and an ATX power
supply.

and what cost do you put on a human life?


That's been a routine job in cost-benefit appraisal for decades.Â* But
it's true that many would disagree with eg NICE's use of about £30,000
for a year of good quality life - especially when it's their life


It costs more than that to keep a prisoner in a cat B rated prison per year.



--
Adam

On Saturday, 20 July 2019 10:49:21 UTC+1, Tricky Dicky wrote:

but you also have to factor in the risk of a power surge causing harm.
I've only lost 2 bits of kit in 30-odd years: a PVR and an ATX power supply.

The risks of power surges seems quite low, to my knowledge I have never experienced one certainly not one that has resulted in damage or injury. It seems that the IET is getting to the point of trying to eliminate any risk no matter how small.

They're creating a risk many times the size of any risk that might be reduced.

To be honest it seems more faff to do the CRL calculation and the risk assessment than to stomp up the money and the few minutes to fit the device.

Richard

Even less faff to not waste the time.

On 20/07/2019 14:43, Robin wrote:
On 20/07/2019 14:31, wrote:
S.f.a I should think!


Indeed.Â* But Adam /is/ based in S. Yorkshire where they

don't get much lightning compared with some other places.

There's even less lightning in mist of Scotland - but of course
correlation doesn't imply causation



I have only been stuck by lightning once.


--
Adam

ARW wrote:

Andy Burns wrote:

£90 per AFDD that AFAIR john ward couldn't force to trip on very
obvious arcs? hmm.

Guess how many I have fitted on a domestic property?

Looks like he's gearing up for more AFDD tests

https://youtu.be/TVqi6CedMkM

On 20/07/2019 18:47, Andy Burns wrote:

ARW wrote:

Andy Burns wrote:

£90 per AFDD that AFAIR john ward couldn't force to trip on very
obvious arcs? hmm.

Guess how many I have fitted on a domestic property?

Looks like he's gearing up for more AFDD tests

https://youtu.be/TVqi6CedMkM


Car charging.


--
Adam