Use of FP200. Will it get messed up by too much flexing?

[1Justin]

I have electrics to add in a listed barn. It's a unlined shell of a building, grubby cobwebby beams and timbers with external claddding. Customer must have all black wiring so as to hide it as much as possible. Everything will be clipped with metal accessories. Trunking/conduits are too big and because the whole building is utterly wonky, nothing which is straight or right angled will fit anyhow.
The BLACK thing has me going, so prevents T&E.
I immediately said to the customer I could run it in H07RN-F which is defined as "heavy duty" (Hence OK for permanent wiring re 521.9.1 and BS50565-1. ).
The slimmer, cheaper and easier to use H05RR-F (Which is most rubber cable in distributors) is not defined as "heavy duty" but merely "tough". This gets into semantics, but sticking with the regs and BS50565-1, I must have "heavy duty" (that does seem to be a technical terminology) cable for permanent wiring. Hence will probably make myself insist on H07RN-F

An alternative might be black FP200. I have to admit I've not used FP cable in the past. My thinking is, I'll be up a ladder and scaffold looping and flexing this round 300 year old dirty beams. I'm concerned that the FP200 being stiff with it's alloy tube will end up a complete mess if it gets flexed much during install. - Would I be right in that prediction?

 

[davesparks]

NOTE:HO7RNF is actually a flexible cable so you should imo avoid that for fixed wiring. (Unless you really fancy bootlacing EVERY end?)

Why avoid flex for fixed wiring?

 

[1Justin]

Why avoid flex for fixed wiring?

No real need AFAICT, provided it's "heavy duty" 521.9.1 (which leaves I think according to this definition only H07RN-F) but it needs lots of clips. Saying that, in a totally wonky timber barn space where the customer will be frowning at visible bits of cable, being able to bend it easily without kinking sideways or having to keep it flat while threading it about. (T&E), I see advantages in flex. I agree ideally should be bootlaced which is a bit of a pain.

 

[Deleted member 109422]

Okay, I have admitted elsewhere on this forum that I am an idiot, but I am an old thick skinned idiot who can take a bit of stick so here goes...

What on earth is boot-lacing?

Is it just doubling up the end of a cable at the connection point? If so then this generally needs to be done with T+E if there is only one cable in a switch or socket.
Go on....shame me. I do not know the meaning of boot-lacing.

While I am here....clipping a flexible cable around beams and trying to hide cables is going to be HUGELY easier than using FP.

All the best,
Sym

 

[Deleted member 109422]

Is boot-lacing twisting the strands of the flexible cables together?
Which is what I would do when connecting multiple flexes.
Note...I would never twist T+E cables together.

Twisting flexible cables together is not that much of a pain in the bum.

Using FP200 can definitely be a pain in the bum.

Sym

 

[Spoon]

Go on....shame me. I do not know the meaning of boot-lacing

Bootlace Ferrules. Used on multi-stranded cables.
Something like this kit here

 

[Deleted member 109422]

Spoon.
oh bloody hell, that shows how behind with stuff I am, blush.

So, do all connections of flexible cables now need a crimp on the end?

I.E....connecting an immersion heater with some buytle or other heat resistant cable needs to be crimped?

Cheers for the reply Spoon, it is another learning day at Chez Sym

 

[telectrix]

Spoon.
oh bloody hell, that shows how behind with stuff I am, blush.

So, do all connections of flexible cables now need a crimp on the end?

I.E....connecting an immersion heater with some buytle or other heat resistant cable needs to be crimped?

Cheers for the reply Spoon, it is another learning day at Chez Sym

you use bootlace ( otherwise known as ferrule) crimps where fine stranded cable is terminated in a screw terminal. this is the ensure that all the strands are in contact with the terminal, and no whiskers.
i use this crimp tool as it's self adjusting as regards size.
Crimper Plier Set 0.25-6.0mm Adjustable Ratchet Wire Crimping Cord Pin End Tool | eBay - https://www.ebay.co.uk/itm/Crimper-Plier-Set-0-25-6-0mm-Adjustable-Ratchet-Wire-Crimping-Cord-Pin-End-Tool/322994537589?_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D2%26asc%3D49138%26meid%3D583a79fc10cd4a9caffd1d14a8a2c113%26pid%3D100012%26rk%3D5%26rkt%3D12%26sd%3D153019091412%26itm%3D322994537589&_trksid=p2047675.c100012.m1985

 

[Deleted member 109422]

Thanks Telectrix.
So am I right in saying that if the OP uses a flexible cable to wire out this barn conversion all connections would have to be crimped?

Yes, as stated above and elsewhere I am an idiot.

If this is the case then shallow metal switch boxes would have to be replaced with metal single socket boxes to accommodate for the depth taken up by the crimp when connecting a one-way switch?

Thanks for your time
Sym

 

[1Justin]

..all connections would have to be crimped?
Sym

More a matter of sound connections and good practice. No "have to" about it though.

 

[Deleted member 109422]

Cheers guys for your patience.
So in reality all domestic immersion heaters and storage heaters should be "boot-laced"?
Sym

 

[davesparks]

Is boot-lacing twisting the strands of the flexible cables together?
Which is what I would do when connecting multiple flexes.

I assume he means fitting boot lace ferrules to the stripper ends of the flex, which is the correct way to terminate flex into screw terminals as it prevents the spread of the strands and stops the screw from cutting through the strands.

 

[Deleted member 109422]

Thanks Dave, yes I think I understand this now.

Sym

 

[davesparks]

If this is the case then shallow metal switch boxes would have to be replaced with metal single socket boxes to accommodate for the depth taken up by the crimp when connecting a one-way switch?

Thanks for your time
Sym

Not necessarily because plain ferrules don’t extend any further back than the stripped end of the insulation, it’s only bootlace ferrules which have a plastic collar.
Either way it is very rare to see a 16mm box used these days as very few dimmers or decorative switches actually fit on them.

 

[Deleted member 109422]

Thanks for the information and input Dave, it has been a while and I didn't realise that shallow metal switch boxes were no longer installed.

Cheers
Sym

 

[alasdairp]

I love working with FP200 Gold - I find it a real pleasure to work with. It is fully approved by BASEC for commercial and residential installations. Because it has a continuous CPC sheath, its use is not restricted to normal wiring "safe zones", though common sense needs to be used. It is also ok for surface wiring without covering - though only white (I think) is OK for external routes without conduit or other cover due to UV issues.

FP200 Gold has a better material for the internal wire sheaths c.f. 'No-Burn Platinum' which uses neoprene (I think) and is easy to damage mechanically.

As an earlier post stated, best way to strip is to score carefully around with knife (you do not want to cut right through it) and then gently bend backwards and forwards and then the outer covering breaks free and can be easily slid off.

I see no need for a ferrule and you would have to abuse it quite a lot to damage the foil CPC layer - there is a normal CPC wire run alongside the foil layer.