2.5mm flat cable with a sleeved CPC

[John-SJW]

I recall seeing this a long time ago. Is it still available? Anyone know.

 

[LastManOnline]

Discussion about Irish T&E was covered in this thread, some time back, which included some additional information.

Good thread you linked to there. Since that was posted we have fully transitioned to using the new T&E. The big issue was getting used to new containment sizes.(wavin, mini trunking etc).The ROI 2.5mm T&E is physically the same size as the UK 6mm T&E.
However we are now enjoying the advantages of no sleeving and no more complicated mathematics when filling in test record sheets. We'll worth the "17%" extra copper pc1966 mentioned. In my opinion

 

[nicebutdim]

Good thread you linked to there. Since that was posted we have fully transitioned to using the new T&E. The big issue was getting used to new containment sizes.(wavin, mini trunking etc).The ROI 2.5mm T&E is physically the same size as the UK 6mm T&E.
However we are now enjoying the advantages of no sleeving and no more complicated mathematics when filling in test record sheets. We'll worth the "17%" extra copper pc1966 mentioned. In my opinion

New installations should have no down side, other than increased cost.

Where I could see it being a real pain is rewires. Pulling two legs of Irish 2.5 T&E through 20mm conduit isn't going to happen.

 

[ipf]

New installations should have no down side, other than increased cost.

Where I could see it being a real pain is rewires. Pulling two legs of Irish 2.5 T&E through 20mm conduit isn't going to happen.

Strip it and you could use it all as singles...? ?

 

[LastManOnline]

Where I could see it being a real pain is rewires. Pulling two legs of Irish 2.5 T&E through 20mm conduit isn't going to happen.

Rewires are a pain... period. In truth it would be rare to get 2 legs of the UK t&e through 20mm pipe (unless it's round rather than oval). But what I do is pull a single leg through and try and plan the circuit so that particular socket ends up as the last point on the radial

 

[i=p/u]

Radials galore, 2 bed apartment. one for.living room, one for each bedroom , 1 for kitchen, then microwave, w/m and d/washer all on one radial on a 3 gang linked grid switch.
No shitty sleeving tho.

 

[nicebutdim]

Rewires are a pain... period. In truth it would be rare to get 2 legs of the UK t&e through 20mm pipe (unless it's round rather than oval). But what I do is pull a single leg through and try and plan the circuit so that particular socket ends up as the last point on the radial

Pretty much standard practice up here to use round conduit bushed into boxes.

 

[nicebutdim]

Radials galore, 2 bed apartment. one for.living room, one for each bedroom , 1 for kitchen, then microwave, w/m and d/washer all on one radial on a 3 gang linked grid switch.
No shitty sleeving tho.

Still need 2 legs on all but the final point ?

 

[i=p/u]

Concrete jungle, launched down back.of a stud wall.

 

[John-SJW]

New installations should have no down side, other than increased cost.

Where I could see it being a real pain is rewires. Pulling two legs of Irish 2.5 T&E through 20mm conduit isn't going to happen.

The cost may not increase, as if it makes the job quicker labour times are reduced.

 

[Mark42]

I built a house in Phuket, Thailand a few years back.

They have as standard a flat T&E with insulated CPC, in horrible American colors, made locally and called 'Three core'. It's surprisingly good quality.

Apparently this is a common configuration in Asia.

 

[Risteard]

Twin and earth cable, 6242Y, with smaller cpc, has never been produced as such.
6193Y with 3 cores of the same size and insulated earth is available and meets the ROI requirements, I believe.

It only meets I.S. 10101 Rules now if the I.S. 201-4 cable is to Dca, -a2, s2, d2 or higher standard. (LSF cable essentially.)

 

[Risteard]

I would be genuinly interested to know what the reasoning/justification was for ROI adopting the same size of CPC and pushing up costs. Anyone know?

My assumption is that it was for increased harmonisation with European and other worldwide practices. It's probably fair to say that the reduced cross-sectional area cpc is a bit of a UK anomoly, notwithstanding the inherent safety of it where disconnection times are met (although it will result in higher touch voltages).

 

[Risteard]

BASEC do not approve cables that do not meet UK standards, so I read.

Not quite true. They also run approvals to Irish Standards. This doesn't mean that these meet BS.

 

[DPG]

Thanks to Risteard for getting the thread back on track. It seemed to have deviated back to a copy of the famous Wago/ring thread.

 

[pc1966]

My assumption is that it was for increased harmonisation with European and other worldwide practices. It's probably fair to say that the reduced cross-sectional area cpc is a bit of a UK anomaly, notwithstanding the inherent safety of it where disconnection times are met (although it will result in higher touch voltages).

I guess harmonisation is the most likely reason. It often explains decisions that don't strictly make sense but make life easier for someone else (e.g. cable manufacturers).

I'm not sure the touch voltage difference matters much in practice, as the usual specification is 0.4s for TN earthing where you would imagine a fraction (50% to 80%-ish) of Uo being present on metal objects during a fault, and 0.2s for TT when to all intents and purposes you get the full Uo supply present.

But the reality is any circuit using MCBs for OCPD, and that is going to be every new domestic install and the vast majority of commercial/industrial final circuits, is going to clear in 0.02s or less if it meets the ADS specification at all.