CU Entry, Old 1980s cable (?)

[davesparks]

I think I'm stuck again, I need 9 cables to enter the new CU but these cables are 20mm X 10mm and most entry points are 20mm x 20mm.

So drill bigger holes in the box!

 

[davesparks]

So the options I identified were:
1) Some sort of grommet specific for this oval cable
2) Perhaps the whiska membrane grommets work, never seen them before. Sounds like they will.
3) Worse case scenario I have a box next to my CU that crimps all these cables into new grey twin & earth, which would then be more normal for entering the CU.

I think Wiska it is. No one has recognised this cable yet then?

Why woukd you need a special grommet? The usual round open grommet you'd use with other cables will be fine.

Why do you think adding extra joints in to the circuits woukd be a good idea? You'd still need a suitable grommet or gland at the entry to the joint box.

 

[westward10]

If the cable inside is Twin and earth, not singles as I thought, (maybe another system) then just trim the outer coloured sleeves off at the wall and treat the T&E as normal.

Absolutely not T&E within that whatever it is.

 

[jon557]

I shall give standard grommet a go, it's just going to be tight as the oval cable is 20mm and most holes are 20mm, the grommet will use 1-2mm, I'll just have to squeeze the cable a bit.

 

[jon557]

Thanks for the help chaps. Clearly my 1986 building is a little special haha

 

[Timbo]

I remember that stuff being introduced in the late 80's. Never really took off as it was fairly expensive.

 

[A032701]

if its to big you could use some m32/25mm glands instead

 

[richy3333]

AFD on a ring final?
Why not just terminate that cable into some trunking or an adaptable box and then bring it into the CU else use a plate to raise the CU off the wall for rear entry?

 

[Wilko]

I'd ditch the lot .

 

[telectrix]

I'd ditch the lot .

why?

 

[davesparks]

I shall give standard grommet a go, it's just going to be tight as the oval cable is 20mm and most holes are 20mm, the grommet will use 1-2mm, I'll just have to squeeze the cable a bit.

Standard grommets are available up to 50mm diameter.

 

[john waters]

we used to call it pre wired conduit. if i remember correctly 25mm knock out and grommet and give it a little squeeze

 

[John Arnold]

AFDD are not for use on ring mains as a series arc fault will not be detected. Use it on a radial circuit only or better still save your money as it is not necessary in your installation (unless you are listed in regulation 421.1.7

 

[Toneyz]

It is Aricon pre-wired conduit thick outer jacket like T & E with three individual compartments with singles prewired into. It came on drums I think. Never used it but got given samples when it used to be advertised in P.E mag every month. Used to be used in some council new builds and flats but in reality was not rewirable as to push a new cable down and through.

 

[pc1966]

Never seen that orange stuff before!

For info AFDD do detect faults on ring finals, just not a ring-break as very little arcing occurs (after all only a volt or two will be there). From Hager's page:

"Contrary to common belief, AFDD’s do offer protection against arc faults in ring final circuits and to the equipment being fed from this circuit. A series arc fault in one leg however, is unlikely to be at a dangerous level so will not be detected. This is due to current in this instance flowing around the other leg of the ring. A series arc fault will be detected in equipment and in flexible cables connected to the ring final circuit. Parallel arc faults are detected and disconnected in all parts of the ring circuit and on all connected equipment."

Arc Fault Detection - Hager UK

Arc fault protection devices (AFDD) use microprocessors to identify characteristic current flow and voltage curves that indicate an arc fault and automatically trip the affected circuit.

hager.com

 

[7029 dave]

I remember that horrible stuff, used alot on council work in the late 60's 70's, solid single core cable incased in that pvc outer channelling/trucking.
Apparently is/was supposed to be rewireable once installed in its screed etc.
Have always seen it just cut out snipped tight.!!