LSF, is there a regulatory requirement?

[GBDamo]

I've been installing this stuff for years in commercial settings, it seems a no brainer.

For the first time, today, a client questioned its requirement and, to be honest I cant find anything in black and white to back up my assertion.

I know the advantages, and tried explaining these but he's adamant if its not legally required, he don't want it.

In this case the peace of mind would amount to ~£150 in a 1/2million pound project.

So, have I been talking gonads or is there something more concrete?

 

[Dustydazzler]

We have been using LSF for everything other than domestic and I have never had anyone question it

That said if someone asked me for the regs number which calls for LSF cable

 

[Julie.]

Nope, no legal requirement, except in particular circumstances.

This is only where std PVC is unsuitable for whatever reason.

I usually specify PVC, for cost reasons, but of course would accept/prefer lsf if the overall cost was the same/lower - depending upon the assessment of the bid.

 

[Dustydazzler]

Not a reg but I just copied this of a cable manufactures webpage

• The low smoke generation ensures evacuation routes and signage remain visible during a fire.

 

[ipf]

When we use it, it's usually specified, although treated as standard if T+E is used in commercial installs.
As above, not a regulation requirement.

 

[Dustydazzler]

On any site I have worke dover the past 25 years be it commercial / industrial If you saw a sparks using pvc twin and earth to wire up a circuit you would class it as badgers rough as...

 

[ipf]

On any site I have worke dover the past 25 years be it commercial / industrial If you saw a sparks using pvc twin and earth to wire up a circuit you would class it as badgers rough as...

There can be different situations where it suits. In commercial kitchens it's usually conduit or swa but there are occasions where LSF T+E is more suitable, Maybe where whiteroc is being fitted, for instance. It meets requirements. Like any form of installation it could be classed as dog rough....depends on the class/state of installation, to me.

 

[telectrix]

pain in the arse to strip it though.

 

[ipf]

pain in the arse to strip it though.

.....and the fingers!

 

[GBDamo]

pain in the arse to strip it though.

Not with these...

If I get a year out of a pair I'm happy, treat em as a consumable but they are worth their weight in gold.

 

[ipf]

Not with these...

View attachment 99670


If I get a year out of a pair I'm happy, treat em as a consumable but they are worth their weight in gold.

Are they okay for stripping three foot or more of the stuff in a big 3 Phase DB?

 

[GBDamo]

Are they okay for stripping three foot of the stuff in a 3 Phase DB?

Yes, it take a fair tug to pull it off but it does come eventually.

Also leaves a nice neat end which helps to keep the cable under neat.

 

[pc1966]

Yes, it take a fair tug to pull it off but it does come eventually.

Also leaves a nice neat end which helps to keep the cable under neat.

Given patience you just strip a bit and pull it off, then repeat until enough.

I have the CK equivalent and find it great for T&E as it gives a neat finish on the sheath and you can use it on the conductors. However, the cable cutter/crimp bits between the handles are a pain as they sometime nip your palms, so I took an angle grinder to my ones to take the worst of the bits off. Utterly useless are crimping the R/B/Y style of insulated terminals anyway.

 

[ipf]

patience you just strip a bit and pull it off, then repeat until enough.

Quicker stripping via the earth core then, although I'm not struck on the method.

For grey I still strip with a controlled knife between earth and another core but that's ridiculously hard with LSF.

 

[GBDamo]

Quicker stripping via the earth core then, although I'm not struck on the method.

It's how it's been done for eons, it ain't called twin & stripper for nothing.

I'm a convert though, especially with TP boards in a tight cupboard when you can't fully extend you're arms, CPC ends up looking like spaghetti, and you spend far too much time trying to get your 2mm* earth sleave on.


* anyone using more that 2mm, on anything smaller than 10mm², has quite simply lost their way in life.

 

[pc1966]

There is something in 422.2.1 on cable characteristics (and trunking, etc) for smoke control but only for 'protected escape routes'.

 

[Julie.]

For grey I still strip with a controlled knife between earth and another core but that's ridiculously hard with LSF.

And completely frowned upon by the "authorities" i.e. training colleges and the like, use a knife in any circumstances and they throw a fit!!

It's they way I have always done it, and prefer it above anything else.

 

[ipf]

And completely frowned upon by the "authorities" i.e. training colleges and the like, use a knife in any circumstances and they throw a fit!!

It's they way I have always done it, and prefer it above anything else.

Yeah, I know That's because, these days, they don't trust a trades person with a ring spanner, let alone a pen knife.
You do it the way you're taught...or always have done, with a bit of skill and judgement.
When I see the disgraceful state of many terminal positions.....

I wonder how they advise stripping LSF swa, these days? Have a job on designing a special tool for that.

 

[ipf]

It's how it's been done for eons, it ain't called twin & stripper for nothing.

Don't I know it. Mind you, the only twin strippers I remember were at a small night club round our way, in the seventies.

 

[telectrix]

Not with these...

View attachment 99670


If I get a year out of a pair I'm happy, treat em as a consumable but they are worth their weight in gold.

got the identical one myself. Klein. still a pain with lsf. I do 2" at a time. also use a knife at times. (shh .H&E may be watching).

 

[GBDamo]

got the identical one myself. Klein. still a pain with lsf. I do 2" at a time. also use a knife at times. (shh .H&E may be watching).

Have you modified the depth gauge?

When I say modify I mean remove the circlip, pull the flaming thing out and bin it.

A joy ro use once modified.

 

[Vortigern]

I was taught at college to use a (electricians) knife and even told it is the difference between a craftsman and an electrician! Of course we were told we are not allowed to use a stanley knife due to H&S reasons Being the blade is brittle and could snap. Tried showing some traines this and one said it's a load of B--------ks. Still I could strip faster than him anyway. But he was doing it with ripping the earth out. Wouldn.t accept a difference in fault levels could potentially result. He's probably right, or wrong. Sorry I am rambling I will shut up now.

 

[Vortigern]

Oh yeh, I only use LSF when specified which is most of the time in commercial.

 

[nicebutdim]

For grey I still strip with a controlled knife between earth and another core but that's ridiculously hard with LSF.

I'd routinely use a knife to strip Hi-tuff or SWA bedding in this way, but would never think to do so with T&E.


Also bought a roll of LSF 3 core today as it was cheaper than PVC.

 

[Dustydazzler]

I'd routinely use a knife to strip Hi-tuff or SWA bedding in this way, but would never think to do so with T&E.


Also bought a roll of LSF 3 core today as it was cheaper than PVC.

Likewise the other week my wholesaler sold me a 100m drum of 2.5 lsf for less than pvc
I love using LSF , i feel all posh using it on a domestic and yes its tougher to strip but with an auto stripper its no problem

 

[nicebutdim]

Likewise the other week my wholesaler sold me a 100m drum of 2.5 lsf for less than pvc
I love using LSF , i feel all posh using it on a domestic and yes its tougher to strip but with an auto stripper its no problem

Never used the stuff, although work with LSF singles day and daily.

Shouldn't be too much of a hardship as I've only 4 ends to strip on longish runs to an intermediate switch

 

[ipf]

I'd routinely use a knife to strip Hi-tuff or SWA bedding in this way, but would never think to do so with T&E.

I understand that but it's all about how you've always done it..and having the basic skill and confidence to carry it out.
If you're frightened of taking chunks of insulation off line cores because you can't control a knife, then fair enough, don't do it.
I can't juggle so I don't do it, especially with knives.

 

[nicebutdim]

I understand that but it's all about how you've always done it..and having the basic skill and confidence to carry it out.
If you're frightened of taking chunks of insulation off line cores because you can't control a knife, then fair enough, don't do it.
I can't juggle so I don't do it, especially with knives.

Just never crossed my mind to strip T&E with a knife. Makes sense I guess, especially with larger sizes, and knife control is essential for any shape of cable - possibly moreso with round as outer sheath continually varies in thickness when stripping in a straight line.

 

[pc1966]

I can't juggle so I don't do it, especially with knives.

 

[pc1966]

Just never crossed my mind to strip T&E with a knife. Makes sense I guess, especially with larger sizes, and knife control is essential for any shape of cable - possibly moreso with round as outer sheath continually varies in thickness when stripping in a straight line.

I have done it that way but usually just part-cut the sheath to make it easier to use the CPC as a rip-cord. A knife is handy but also very easy to nick the primary insulation, sadly done that a bit too often and had to cut and strip again

 

[Julie.]

I have done it that way but usually just part-cut the sheath to make it easier to use the CPC as a rip-cord. A knife is handy but also very easy to nick the primary insulation, sadly done that a bit too often and had to cut and strip again

The way I was taught was to "ring" the outer sheath where you needed to stop, then go between neutral and cpc, angling the blade towards the cpc, it slides smoothly along the bare copper, so easily the issue isn't nicking the neutral insulation, but going too far!

Once you get to the ringed part, stop at or before it, then pull the outer off the line and neutral and it snaps off giving a perfect end without the uneven sheath end that appears inevitable when tearing the cpc through the sheath.

It's very quick once you have the technique, every bit as quick as tearing the cpc, (assuming you do or do not ring the sheath in both methods)

 

[Vortigern]

The thing to remember on using a knife is that you are not cutting but scoring. So having scored around the sheath that is plenty enough does not take much pressure then snap the cable sideways and it splits at that point. Again you only need to score down the sheath to then pick the earth out and use it as a rip cord on the scored part and it comes out with very little pressure required.

 

[dennisbrown]

Just never crossed my mind to strip T&E with a knife. Makes sense I guess, especially with larger sizes, and knife control is essential for any shape of cable - possibly moreso with round as outer sheath continually varies in thickness when stripping in a straight line.

controlling a knife to cut the sheath ? Controlling is even a deal, my first month apprentice can do it quiet easily

 

[Electro-tech]

I have used LSF cable when specified but after reading below I think it may well have to be LSHF depending on the manufacturer.

What is LSF cable?​

If burning PVC cables present such a potential hazard to life then surely cable labelled and marketed as Low Smoke & Fume, or LSF as it’s commonly referred to, provides the answer. Unfortunately that’s not the case, as LSF is also manufactured using PVC compounds. The PVC in question is modified to varying degrees dependant on the manufacturer’s choice of additives, but generally it still produces fairly high volumes of dense black smoke and HCl emissions. In truth there is little by way of standards to dictate what the emission differentials between LSF and PVC cables should be, which explains the wide variation of results when tested; some LSF products producing 15% HCl while others are responsible for up to 24%. In short, LSF flexible cable’s a bit like Forrest Gump’s box of chocolates – ‘You never know what you’re gonna get’.

 

[nicebutdim]

controlling a knife to cut the sheath ? Controlling is even a deal, my first month apprentice can do it quiet easily

Welcome to the forum. Perhaps if you'd read all posts, rather than take one in isolation, conversations will make more sense.

T&E that we use in the UK is a flat cable, similar to Romex. As such there are many means of stripping it that are much quicker than using a knife. Knives certainly have their place and I use one daily for stripping various types of cables - just not flat stuff.

 

[Dustydazzler]

Welcome to the forum. Perhaps if you'd read all posts, rather than take one in isolation, conversations will make more sense.

T&E that we use in the UK is a flat cable, similar to Romex. As such there are many means of stripping it that are much quicker than using a knife. Knives certainly have their place and I use one daily for stripping various types of cables - just not flat stuff.

I have seen quite a few Americans / Canadians on Youtube split a twin and earth ( Romex ) by gidding a sharp knife straight down the centre line. I don't like this method if you go slightly off centre you will cut into the insulation of the cores

I really don't like this method

 

[nicebutdim]

I have seen quite a few Americans / Canadians on Youtube split a twin and earth ( Romex ) by gidding a sharp knife straight down the centre line. I don't like this method if you go slightly off centre you will cut into the insulation of the cores

I really don't like this method

I used a knife to strip a few T&Es after the conversation with @ipf

While I'd routinely split sheaths of NYY etc with a knife, it didn't strike me as the best method of stripping T&E. A number of colleagues nibble the sheath of flex with side cutters, whereas I'd use croppers to ring most round cables, then pull the sheath away on short lengths or run a knife down longer lengths. I guess it's a case of horses for courses - and even first month apprentices.

 

[ipf]

I have seen quite a few Americans / Canadians on Youtube split a twin and earth ( Romex ) by gidding a sharp knife straight down the centre line. I don't like this method if you go slightly off centre you will cut into the insulation of the cores

I really don't like this method

I agree, total rubbish way....and dangerous.

 

[ipf]

I used a knife to strip a few T&Es after the conversation with @ipf

While I'd routinely split sheaths of NYY etc with a knife, it didn't strike me as the best method of stripping T&E. A number of colleagues nibble the sheath of flex with side cutters, whereas I'd use croppers to ring most round cables, then pull the sheath away on short lengths or run a knife down longer lengths. I guess it's a case of horses for courses - and even first month apprentices.

I do hope that you weren't presuming that was my method of knife stripping T+E.........it's horrid.

 

[nicebutdim]

I do hope that you weren't presuming that was my method of knife stripping T+E.........it's horrid.

Hadn't watched the video and, no, that's not at all what I had in mind. It's brutal - I've never seen anything like it!

 

[Dustydazzler]

Hadn't watched the video and, no, that's not at all what I had in mind. It's brutal - I've never seen anything like it!

Another butcher at work Look away now if you are squeamish

 

[nicebutdim]

Another butcher at work Look away now if you are squeamish

These people are mad - might as well use a grinder.

 

[littlespark]

I use a knife between cpc and A.N Other core to start off… far too easy to misalign and remove some of the inner insulation if going all the way.

Give myself a few inches to hold onto, and pull the L and N apart.



Did it once as a naive apprentice in a live 3ph board. Cpc coiled up and slipped between the gap beside the MCB’s that were fitted…..

No more cpc of any considerable length!