0 members (),
181
guests, and
10
robots. |
Key:
Admin,
Global Mod,
Mod
|
|
|
Joined: Aug 2001
Posts: 7,520
Member
|
I still see some of the old lead-sheathed cable in use from time to time, although it's quite rare now. Also have found the IRV cable in oak or other hardwood capping as described by Trumpy and Paul, had it on the lighting circuits in our old house until 1990,
In old houses, lighting circuits are the most likely places to still find really old wiring methods in use. So many houses have had the circuits for sockets and other devices rewired in more modern times, but lighting circuits are often still original: Rubber singles in thinwall conduit from the 1930s, for example. We've just changed over to the Red/White/Blue 3 Phase colour code over here, it was Red/Yellow/Blue before that. Is this a change back to white though? The old British Standard used red/white/blue. Phase B was changed from white to yellow in 1964. Curiously though, white continued as the phase B color in flexible cords after the fixed cables went over to yellow. As the adoption of green/yellow for earth (in flex only) was in the pipeline, I wonder whether this was done deliberately to avoid having yellow on two conductors. If so though, it would have made more sense to just leave fixed cables with white as well! I don't have all the intermediate amendments here, but the 1966 IEE Regs. still show white for flex, yellow for fixed cables. By 1970 though, flexes changed to the European colors, with brown for all three phases. [This message has been edited by pauluk (edited 06-23-2005).]
|
|
|
|
Joined: Jul 2002
Posts: 8,443 Likes: 3
OP
Member
|
Paul, Is this a change back to white though? Ahaa!, now that is the real question. I've just been looking at the 1961 Regs I have here and it says yellow as the B phase in 3 phase cables. I'll have a look at the 1935 Regs at work tomorrow to see what that says. I don't think that they used colour coding back then, it's hard to say, I'm guessing a numbering system. Who knows?.
|
|
|
|
Joined: Dec 2001
Posts: 2,498
Member
|
Here in Austria where conduit was used they didn't have a color coding until the 1970ies... I've seen a huge main panel with the main fuses for several apartments in a 1900 building. The panel has 1957 scribbled on the door. The circuits for the apartments are wired in various colors, but always the same for all 4 wires, that means one apartment has purple phases and neutral, one has blue, one white... grounds are a mixture of red and mostly yellow-green, so I assume they are a later addition. Some day I gotta take a picture of that panel. It once started as a real nice huge Diazed II and III panel, all wires nicely bundled and everything. Now it is one big mess. Many circuits have been cut off as apartments were joined together and split up again, covers are missing, empty fuse bases without screw caps, wrong labeling,... it's the house with the lead cables and phone patch panel.
|
|
|
|
Joined: Jul 2004
Posts: 145
Member
|
It will however be interesting to see how well this PVC sheathed stuff looks after a few years up in a hot roof void. 2 words Trumpy, at least as regards the older stuff in the UK. Plasticiser Migration. Had to deal with some today on a kitchen remodel, the plasticiser had leaked from the cable where it had been run under the plaster behind a gas stove, the cable sheath was covered in sticky yellow goo, and the internal core insulation was brittle as bakelite. Lovely
|
|
|
|
Joined: Jul 2002
Posts: 8,443 Likes: 3
OP
Member
|
OK Paul, Regulation 44 :(Of 1935) Each conductor of a poly-phase system shall be numbered at either end of the said conductors, this shall be as a label or as some other indelible method. It shall be contrary to the Regulations to paint the conductor insulation. The manufacturer shall provide the marking method One thing that I have learned guys, is the fact that I love reading old Regulations. The oldest we have here is the 1915 (First Institution) although Reefton (do a Google on that) was the first place in the Southern Hemisphere to have a reticulated power supply back in 1890 (I think). I had to get out and do some work though, I could have read for hours though. [This message has been edited by Trumpy (edited 06-24-2005).]
|
|
|
|
Joined: Jul 2002
Posts: 8,443 Likes: 3
OP
Member
|
Comments and picture submitted by Chipmunk: This is a piece of new British Standard 2.5mm twin and earth, with the nice shiny new colour codes, notice however that they're _still_ undersizing the earth wire, pity, they had to retool to do the new colours, they could have put in a 2.5mm earth. I believe the earth to be 1.5mm. Thanks Chipmunk!.
|
|
|
|
Joined: Jul 2002
Posts: 8,443 Likes: 3
OP
Member
|
Just merely for comparison's sake, here is the 2.5mm2 we use here in New Zealand: All 3 conductors are stranded (7/0.67), they don't come pre-twisted like that, I just twisted them up to make the pic a wee bit neater. As I've mentioned before here, our TPS (Tough-Plastic Sheathed) cables have a metre-marking printed on the outer sheath, to tell you how much cable is left on the reel. Here's what it looks like:
|
|
|
|
Joined: Aug 2001
Posts: 7,520
Member
|
The circuits for the apartments are wired in various colors, but always the same for all 4 wires, that means one apartment has purple phases and neutral, one has blue, one white... Hmmm..... Why would somebody have done it that way, I wonder? If there is a need to identify circuits belonging to each apartment (maybe in a floor/celing void where there are conduits for the apartments both above and below), then I would mark the actual conduits at strategic points with tape or paint. they're _still_ undersizing the earth wire, pity, they had to retool to do the new colours, they could have put in a 2.5mm earth. I believe the earth to be 1.5mm. Yes, on 2.5 cable the earth is 1.5mm. Believe it or not, I still haven't actually seen any of this yet! (The local warehouse is stocking it, but they still seem to have miles of red/black.) I've installed some SWA with harmonized colours, and single brown/blue meter tails, but not the new T&E yet. here is the 2.5mm2 we use here in New Zealand: I remember us discussing this before. The main differences between this and UK cable seem to be: 1. You have the phase conductor in the middle. 2. Your 2.5 is stranded, ours is solid. 3. You have a sleeved earth. (Is that plain green, or is there a yellow stripe we can't see?) 4. You have a full-sized earth. OK Paul, Regulation 44 Of 1935) I love reading old Regulations. O.K. then. I can't go back that far on the British Regs., but here's the appropriate section from 1955 on identification of conductors: 206 (A) Every single-core cable and every core of twin or multicore cable, including a flexible cable other than a flexible cord, shall be identified at its terminations and preferably throughout its length. The following means of identification are recognized:
(i) The cores of rubber-, p.v.c.- or polythene-insulated cables shall normally be identified by colour in accordance with Table 7. Alternatively, terminations shall be identified by the application of sleeves or discs of the appropriate colours prescribed in the table.
Table 7 specifies: Earths = Green Neutral = Black Live of 2w cct = Red Phases on 3-ph cct = Red, white, blue And for DC: 2w positive = Red 2w negative = Black 3w positive = Red 3w neutral = Black 3w negative = White It also specifies that the outer -- either positive or negative of 2w DC cct. derived from a 3w cct shall be red. That's a little offputting when red can be negative, but consistent with red being the live on a single-phase AC circuit no matter which phase it's derived from. (ii) Insulated cores of paper- or varnished-cambric-insulated cables shall be identified by means of numbers in accordance with B.S. 480 or B.S. 608 respectively. The standards referred to specify 1, 2, and 3 for phases with 0 for neutral. (iii) Conductors of mineral-insulated cables shall be identified where necessary by the application of sleeves or discs of the appropriate colours prescribed in Table 7.
(B) Bare conductors, other than earth-continuity conductors and earthing leads, shall be identified where necessary by the application of sleeves of discs of the appropriate colours specified in Table 7, or by painting.
(C) The cores of flexible cables shall be coloured throughout as applicable: Red for phase or outgoing conductor. Black for neutral or return conductor Green for earthed conductor.
(D) Where a scheme of colouring is used in a consumer's installation to identify switchboard busbars and/or connections to individual phases or poles, such scheme of colouring shall either conform to the requirements of Table 7 or, if the scheme of colouring complies with B.S.158, any common terminals (after connection) shall be coloured in accordance with Table 7.
I'm not sure of the contents of B.S.158. { Edited for typo! } [This message has been edited by pauluk (edited 06-29-2005).]
|
|
|
|
Joined: Aug 2001
Posts: 7,520
Member
|
Re old wiring in wooden channels, I also found the following in the 1955 Regs. while looking for the above: 227 Any type of cable which complies with Regulation 606, other than varnished-cambric-insulated cable without lead sheath or unprotected aluminium-sheathed cable, , may be enclosed in wood casing provided that the requirements of the following Clauses (A)-(C) are complied with:
(A) Casing shall be used only in dry situations. It shall not be buried in plaster or cement, it shall not be fixed in contact with gas-pipes or water-pipes or immediately below the latter, and it shall not be exposed to drip due to condensation or other cause.
(B) The capping shall be secured by screws.
(C) Ready access shall be provided to cables contained in casing, including casing forming part of ornamental woodwork.
Reg. 606 basically sets out the standard sort of cables: PVC or rubber-insulated, impregnated paper, mineral-insulated copper-sheathed, etc.
|
|
|
|
Joined: Dec 2001
Posts: 2,498
Member
|
Hmmm..... Why would somebody have done it that way, I wonder? If there is a need to identify circuits belonging to each apartment (maybe in a floor/celing void where there are conduits for the apartments both above and below), then I would mark the actual conduits at strategic points with tape or paint. Nothing like that... It's just each circuit running in its own conduit up from the basement to the meters for all shops/apartments in the basement and on the ground floor. And it's only the three-phase circcuits that are coded like that, the single phase use the "whatever they had" scheme.
|
|
|
Posts: 806
Joined: October 2004
|
|
|
|