Our house was built in the 1950s.
Wiring appears to be in good condition and not to be rubber.
We recently had a new split load CU installed with both sides RCD protected with no problems. (TT system)
Ring circuits cable is multi stranded. Has the appearance of being copper encased in usual old red/black and outer grey pvc. Green tape was on the earths to the sockets I recently replaced.
Cannot recall any multi-stranded cable in any previous properties. Any comments?
Just an older version of twin and earth cable, seems to fit with the age of the house, you say the insulation is in good condition, so there is no issue.
Many thanks. Just what I was looking for. We have had an earth spike, new CU and new kitchen with a now separate new ring fitted.
Wiring I have found so far all seems OK. Even earths on the lighting circuits. Just replacing the original power sockets with nice new switched MK ones.
Somehow the numbers '7/029' come to mind - 7 strands of 029" diameter; or was that something else (further thought - No! - that was electronic size wire !!!). Many hours spent as a bored teenager fishwiring mains cables through steel conduit for my father in the mid fifties - having spent an equal number of boring hours threading the damned stuff.
The only entertainment was the Polish electrician my father employed who hadn't caught up with the niceties of ring mains and caused a nice big bang when he threw the handle on one of those cast iron main switches. Rob
The present 'solid' 2.5mm TW&E came in around 1970. Metrication. Previous cable was 7 strands of 0.29". Still perfectly serviceable if in good condition. The lighting wiring is also likely stranded - 3 strands of the same diameter. Although a single larger strand (.044") was also used.
Perhaps that was 7/0.029" Dave?
I was only wiring up some banks of 13 amp sockets in my workshop the other day using up some stocks of pvc clad 7/0.029". Much easier to work with than 6242Y solid core. And it comes in 'proper' colours!!
Bob
The difference a 0 makes. ;-)
Invisible Man wrote on 18/11/2009 :
Rubber went between 1950 and 1960 -ish.
Could be 7/029 which was the old imperial size. If so the sockets were probably rewired after the house was built. Though I seem to vaguely remember there was a stranded metric size for a short while, so could be that.
Invisible Man wrote on 18/11/2009 :
That was not common in 1950 or even 1960. Bet it was originally wired in rubber, which had a limited lifetime, then rewired later perhaps mid to late 1960's - just when earthing was becoming more common on lighting circuits.
Oh dear, my mistake. Just checked and house was built around 1966 so wiring is probably original. I was a bit puzzled why it was not rubber or replaced much more recently.
Beg to differ. Don't think I've come across a 1960's install without earths. Even my parents' 1950's PVC install has earthed lighting circuits (although the lighting earths are all brought around the outside of the junction boxes and twisted together tightly with pliers).
My parents had a retirement bungalow built in 1968 (in the garden of their previous home. The lighting wiring all goes back to a large central box in what was then the loft (now converted). All the junctions in the box are those screw-it thingies and all the wiring earths are twisted together and wrapped haphazardly round the outside of the box.
The detached garage, which dates back to the mid 50s, still has one radial circuit in rubber. The rubber shows no deterioration at all, perhaps because it is in an unheated building.
Until I had it rewired my house - first sold in 1965 - had rubber wiring, with no earth wire in the lighting circuits.
Andrew
My house, which I bought new in October 1965, along with the other 50 or so other houses on the estate, have non-earthed lighting.
CRB
That must have been one helluva BOGFF offer. B-)
I started my apprenticeship as an electrician early 1960 and being the apprentice, all the cablework, in houses, was my job. It was all pvc,
7/.029 t&e for rings and 1/.044 twin (no earth) for the lighting. Occasionally 3/.029 was used for the lighting, again no earth, but can't offhand remember under what circumstances. Late 62 I joined the RN and moved over to electronics so don't remember when earth was commonally introduced for lighting.
Should have added that this was mainly at Swindon, then a few months at Brighton but the no earth on the lighting circuits was common to both areas. Can't speak for any other areas though.
PVC sheath with polyethylene insulation
- FTE - sometimes power, more usually clocks
- FT - typically for lights
TRS, rubber sheath & rubber insulation
- FTE - power radials (no rings)
- FT - power, more usually fixed, separate earth wire
There was a rare FTE with the 3rd core insulated along its entire length in green. I suspect this was French or Belgium, black outer. It is solid core & non-tinned whereas all the other cable at that time and size would be stranded core & tinned. The benefit of tinned is corrosion products exclude oxygen where tinned contacted tinned.
Rubber is the best insulation and whilst physically very tough it is very nice to work with re flexibility at installation - contrast with BS7211 LSOH FTE where 2.5mm could really do with being stranded as it is not pleasant to work with. Rubber degrades at terminations, beware what appears sound may be cracked through to the cores to unwary fingers and since there is no CPC in some (FT) it presents a fire hazard as OverCurrent protection will operate rather than Earth Leakage (RCD).
I have been tempted to use 6-10mm H07RNF before now for cooker installs down twisting conduit with bootlace ferrules, however it's not worth the hassle. Tiles pop off easily enough if you do a thin plaster skim before tiling (the tile breaks away taking that thin skim with it rather than the tile breaking, soak overnight, scrape off, refit as need be). Likewise I would have liked to use FP200 red for smoke, but I hate silicone insulation as it is not very robust compared to "genuine" FP200 Gold from Prysmian whose insudite is much tougher to installation handling (does not nick or tear if you so much as look at it).
I didn't know about the pvc and polythene cable, and am not clear on the names or some of the abreviations you use there. Maybe you'd like to offer a note or 2 to add to the wiki article on this?
Just cross-checked the date, and my parents' house was built in
1958 in Reading, and that was all PVC wiring and all earthed. I replaced the CU in 1999, and in the tests I did then, all the original wiring checked out OK. (I had rewired the kitchen.) Similar age houses I came across when I was living in that area were similarly all earthed, so may have varied by area, or builder.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.