Only found 100M drums of it so far on ebay. Thanks to this thread I have a few more keywords for searches now, so I'll have another go.
Stranded seems like a useful feature, though if it's possible to pull
2 T&E cables through the conduit, individual wires must be somewhat easier by comparison.
The joys of being a pro. I'm barely a d-i-yer so I'll have to admire that sort of relationship with wholesalers from afar.
I'll renew my search for a similar local supplier.
Is stripped T&E a realistic option for a small job? If so, does the earth wire have to be sheathed throughout it's length?
Geoff Mills coughed up some electrons that declared:
No - you'd probably want mini trunking for that.
Although you could use 20mm oval to 20mm round adapters and metal clad surface boxes (with 20mm conduit knockouts) - though such adapters are as rare as hen's teeth.
Also, oval conduit is not as robust as round - it really forms a tube in the plaster. On the surface it would be easy to squidge.
Go buy John Whitfield electrical guide. BS7671 OnSiteGuide is a good reference, not a guide.
- Singles (6491X) have thicker insulation than FTE
- Earth MUST be sheathed throughout its length
No.
- For surface sockets use round conduit or mini-trunking.
- Round conduit suits "warehouse bare brick" or looks odd.
Options...
- Run FTE in mini-trunking between surface backboxes
- Sink FTE into wall in ZONE between sunk backboxes w/grommets, cover the plaster cutout cutout with flat wooden bead until redecorated
The latter is much prettier and "lower profile" than mini-trunking which is a ghastly abomination even in d-line.
In general.
- Capping & Oval require sheathed cable (Flat Twin & Earth, FTE).
- Round Conduit can use singles (6491X) or sheathed cable (Flat Twin & Earth, FTE).
- With oval fit a grommet to the backbox, butt the oval up against the grommet
- With plastic round conduit fit female bushes into the backbox, slide the conduit into the bushes
- With steel round conduit you need proper Die (=A325) & Bender (Hilmor =A3250)
- Conduit must be installed prior to cable draw in (so enforcing the rule that if someone got the damn stuff in then when it goes time for replacement someone else can get it out and back in again!)
- Conduit must be continuous where Singles (6491X) are used, you can't stop the conduit short and use a grommet
Plastic conduit is only sometimes used in domestic, 20-25mm oval is flatter. Steel conduit is very rarely used in domestic re expensive tools & labour.
You can buy 20mm oval-to-round adapters, MK do them.
- Trading Depot might list them, =A30.80-1.00 each
- Cable only passes easily through them one way
- Ok for oval-in-plaster-to-round-in-stud-wall-cavity runs
If you need to run a cable outside a Zone.
1 - Consider if a wiring accessory can be added to create a Zone. 2 - Use BS8436 cable such as Prysmian Flexishield or EarthshieldThe problem with BS8436 is =A3120-180 for 1.5-2.5mm/100m.
Example of where BS8436 is useful:
- Light switch below chimney, no-where else to fit it
- a) BS8436 b) MK Echo (=A3180) c) Occupancy PIR (=A350 + =A350 for spare)
- Option a) is best because a switch is more reliable
Example of where BS8436 is useful:
- Room has sloping ceiling so no 150mm HORIZONTAL zone, solid floor
- BS8436 is a lot simpler than wiring accesory route-markers everywhere
TLC are not carrying BS8436 (I asked, they asked NICEIC). No-one else does. Surprised, because "25m" would be a low risk investment for someone to carry.
OP questions indicate he needs to read John Whitfield's book. Go to Amazon UK.
Thanks, that's a lot of very good advice.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.