Need 2nd opinion on cable.......

[Guest55]

this has been bugging me for weeks..........
been using Fp200 for all socket / lighting circuits on current project , the usual 1.5/2.5 stuff
and im almost sure , but not 100% , that the tinned solid core cpc is the same size as the L / N ??
its certainly not a 1mm earth in the 1.5 cable......
had a quick nosey on a cable website but found nowt conclusive.
anyone else confirm or know different ?

 

[tbs1983]

perhaps because it isnt as good a conductor as copper they use the bigger csa size in order to keep earth loop impedance down ??? ( just a though)

 

[Guest55]

it is a copper conductor , but tinned on the outside.
a good point to raise though.

 

[ian.settle1]

Try this link

Prysmian cable provides protection in the City - Edmundson Electrical

Then click on the data sheet link at the bottom

 

[Guest55]

thanks ian but still doesnt mention cpc size like the other cable website i checked.

i can only deduce that the cpc is the same csa as line as a reduced size would need to be noted in the manuf. data.

something needs to be recorded on the cert for earth size so im going with my gut.

 

[Marvo]

Can't you measure the diameter with a vernier and manually calc the CSA?

 

[Guest55]

Can't you measure the diameter with a vernier and manually calc the CSA?

nope , got no verniers..........
but i could measure resistance on a spare piece - if E csa = L csa , then L-N & L-E should be the same on a continuity test

i just thought someone may have come across the same issue previously , especially when the time comes to fill in cert and youre not on site lol.

 

[Marvo]

i just thought someone may have come across the same issue previously , especially when the time comes to fill in cert and youre not on site lol.

I haven't seen a similar question so they've probably just made a wild guess

The resistance method would be pretty accurate especially if you have a longish piece of cable you could also size it using reference tables for copper wire resis/meter.

 

[Guest55]

a wild guess


size it using reference tables for copper wire resis/meter.

i'm leaning towards option 1 on a lazy saturday afternoon lol
;-)

 

[KAS1]

Check manufactures data / your cable supplier, it's no good just being "almost sure" now come on get a grip.

 

[Guest55]

Check manufactures data.

WTF do think i've been doing with ians link in post #4 ?
;-)

 

[Knobhead]

Same size

Buy Prysmian Fire Resistant Cable, Red, 100m, Annealed Copper 1.5mm², Three Core - FP200H1.5RED

 

[MarkieSparkie]

BS 7629 requires fire cable (FP200 etc) to this standard to have all cores of the same CSA.
Firecable BS 7629 - Enhanced | UK Cables

 

[Knobhead]

Fire Resistant
Red
100m
1.38mm (Strand)
100m
Three Cores of Plain Annealed Copper 1.5mm²
1.38mm (Strand)
12.1ohm/km@20C (Conductor)
300-500V

PS Tinned copper is better than plain

 

[Guest55]

Same size

i knew it ! lol , just thought i'd kill time with the ensuing debate. ;-)
marvo's right tho , never seen it mentioned in any other topic which is strange considering its wide range of applications / uses.

 

[ipf]

Is the earth core smaller when you use one of the cores in a SWA ?

 

[GLENNSPARK]

perhaps because it isnt as good a conductor as copper they use the bigger csa size in order to keep earth loop impedance down ??? ( just a though)

no....do you not think the terminal screws wouldn`t get through the tinning?

 

[Guest55]

Is the earth core smaller when you use one of the cores in a SWA ?

no , but then swa isnt the same as fp200 is it ?

 

[MDJ]

A very good question I thought and to answer it the bare conductor is the same size as the sleaved pvc conductors Biff

 

[Deleted member 72666]

I've also come across this when doing a eicr, the lighting circuit in the cellar was in 1.5mm fp200 with a tinned copper 1.5mm cpc, the radial sockets however were fed with a 2.5mm fp200 cable with a 2.5mm stranded tinned copper cpc.

 

[Knobhead]

I’ll say something now.

I’ve never used FP cable or that crazy way of doing 2 way switching and I never will use them. (I’m retired). But I’ve learned several things today, have you?
I very much doubt it!

Members don’t like you’re snide comments, today you have dropped in nearly everyone’s estimation. It wasn’t very good to start with.

Reconsider you’re position and just prey you never have to ask for information.

BTW
I can be downright nasty but if someone asks a question that gets me interested then I’ll help, anyway I can!

 

[Knobhead]

A very good question I thought and to answer it the bare conductor is the same size as the sleaved pvc conductors Biff

Something else I've learnt today. I thought the CPC was sheathed!

Come to think of it I have re-used early FP. Just don’t ask me where!
A substation I think. Don’t know! It’s lost in the mists of time

 

[Spudnik]

​Please keep it civil.

And yes, i have edited/deleted some posts.

 

[Wolfie708]

You do know the easiest way to check (on site that is) would just be grab a coil and your meter and check the resistance of each core on a drum, or see if Line to Earth is same as Line to Neutral............... Just a suggestion if you get any more like this

 

[MDJ]

Hmm, Biffs Pis*ed and I don't mean from alcohol, Thats why he is now quiet in this thread and I don't blame him TBH, you start a genuine thread about a genuine issue or question and the prats again are out just like the thread with Glenn, whats happening here, even the good sparks are getting crap now, god help us

 

[ipf]

no , but then swa isnt the same as fp200 is it ?

..........? :chillpill:

 

[bartkusal]

You do know the easiest way to check (on site that is) would just be grab a coil and your meter and check the resistance of each core on a drum, or see if Line to Earth is same as Line to Neutral............... Just a suggestion if you get any more like this

From experience I know that the size is the same it is just different conductor material,but to test the way you mentioned would not give you any indication of them being thesame or different size,. It will only give a very low Loop L-CPC to compare with L-N, because laminated aluminium tape screen which is bonded to sheath is in constant contact with full size tinned annealed copper circuit protective conductor, so in theory you have 2 CPC’s in parallel if you like.

Al

 

[Knobhead]

I’ll say something now.

I’ve never used FP cable or that crazy way of doing 2 way switching and I never will use them. (I’m retired). But I’ve learned several things today, have you?
I very much doubt it!

Members don’t like you’re snide comments, today you have dropped in nearly everyone’s estimation. It wasn’t very good to start with.

Reconsider you’re position and just prey you never have to ask for information.

BTW
I can be downright nasty but if someone asks a question that gets me interested then I’ll help, anyway I can!

Just to clarify something, the post I was referring to has been deleted.
I do hope no one took offence by omission.

 

[GLENNSPARK]

Hmm, Biffs Pis*ed and I don't mean from alcohol, Thats why he is now quiet in this thread and I don't blame him TBH, you start a genuine thread about a genuine issue or question and the prats again are out just like the thread with Glenn, whats happening here, even the good sparks are getting crap now, god help us

let `em come Mike....i`m quite capable of stamping on most of em...

 

[markc123]

Glenn the EF residence rottweiler lol

 

[Geordie Spark]

Glenn the EF residence rottweiler lol

Nah!! ............ he's a Yorkshire Terrier!!


(for the record, Wor Lass thinks I'm like a Weimaraner - whatever that is)

 

[telectrix]

Nah!! ............ he's a Yorkshire Terrier!!


(for the record, Wor Lass thinks I'm like a Weimaraner - whatever that is)

i had you down more as a gypsy's dog.....

 

[tidyboiler]

Nah!! ............ he's a Yorkshire Terrier!!


(for the record, Wor Lass thinks I'm like a Weimaraner - whatever that is)

Grey and grumbles a lot. :earmuffs:
................ not really, you are like a big, soft hearted alsation. You look fierce but are aways ready for a belly rub ....:smilewinkgrin: