OK we've talked about MIMS and a few other cable types here.
Anyone else care to submit some cable types for discussion?.
If you have pictures all the better.
Please submit them to me or Paul or C-H for posting here.
Cheers,
Mike.

Funny you should bring this up. I tried to buy some highly flexible cable a couple of weeks ago. (3 x 16 mm2) Miminum order was on the order of 300 m which was three times as much as I needed. They could get me 3 x 25 mm2. I called the next manufacturer only to get the same answer. Confounded, I called another one and got the same answer an third time.

I finally ordered with the first manufacturer. The cable arrived Tuesday and I noted, somewhat surprised, that it had been shipped from the second manufacturer I had called. Apparently the manufacturers cooperate to some extent and had been pointing to the very same cable drum somewhere in Germany.

Some manufacturers will make a cable entirely to your specifications if you buy 3 km / 10' feet or more.

I din't take any photos. Bugger!

One sort of cable system I still see a wee bit of over here, is the old cloth-covered rubber wires inside wood casing, it used to be used here for Service Lines into the main switchboard here.
Thankfully most of it has been removed these days, I accidently stood on a length of it when working up in a roof once.
Man did it go off with an explosion!!, the casing was only just holding the (now bare) wires apart inside and once disturbed, look out!.
Worse still, the heat from the explosion ignited the wood splinters.
I really watched what I stood on up in roof voids after that.
C-H,
That would be a surprise!.
We have a cut-to-length service here for most types/sizes of cable.
Sure, it does cost a bit more, but it saves wondering what you're going to do with what's left over, especially if it's a really odd type of cable.

A similar method was used here in the early days. Cables were run in grooves in the wood, then a cover fixed over the top. There might still be some of it in use in a very old property which hasn't been rewired, but I haven't seen any of it for years.

The earliest wiring methods I've seen here were: individual cloth and rubber covered wires in isolators (glass or porcelaine), twisted lamp cord style wire on isolators.
Later on they used tar impregnated cloth wire, either in Bergmann conduit (basically asphalted cardboard with a thin metal sheathing around) or just in plaster. That wiring method was used until the advent of PVC insulated wires in the 1950ies. Bergmann conduit survived until around 1960.

Some months ago I found a place where somebody had tried to "replicate" the old wiring... by twisting blue PVC-isolated conduit wire and stringing it up on a few nails down in the moist basement... good thing the house was scheduled for demolition just a few days later... (but just for the dodgy wiring, otherwise it was a real shame for the old rock-solid 1900 brick house!!!)

Mike,

here they will cut it to lenght if it is in stock. If they have to make it for you they won't. How much you need to buy depends on the price and how busy they are. I suppose it takes to long to set up the machines to make only a few metres of cable.

I lived in a tenement flat in Edinburgh as a student, that had cabling that looked like normal T&E except it had a lead jacket. But then the heating was an original victorian open coal kitchen range and the bath taps had 1881 and 1882 stamped on them.

Gideon.

I have come across the lead sheathed wiring before, the rubber insulation inside the sheath was in very good condition considering it was nearly 60 years old.

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, when it shorted out above a light fixture and nearly set fire to the attic

I left some of the capping in place, the grooves were just the right size for 1.5mm Twin and Earth

Posted for Chipmunk:





[This message has been edited by Trumpy (edited 06-23-2005).]

Oddly enough Chipmunk,
We've just changed over to the Red/White/Blue 3 Phase colour code over here, it was Red/Yellow/Blue before that.
Regarding your comments on TRS (Rubber Sheathed) cables, rubber sheathed cables are quite quite hard-wearing as long as they aren't subjected to too higher temperatures.
It will however be interesting to see how well this PVC sheathed stuff looks after a few years up in a hot roof void.

I still see some of the old lead-sheathed cable in use from time to time, although it's quite rare now.


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.
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).]

Paul,
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?.

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.

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

OK Paul,
Regulation 44 :(Of 1935)
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).]

Comments and picture submitted by Chipmunk:



Thanks Chipmunk!.

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:

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.

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.

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.


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:

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.

The standards referred to specify 1, 2, and 3 for phases with 0 for neutral.

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).]

Re old wiring in wooden channels, I also found the following in the 1955 Regs. while looking for the above:


Reg. 606 basically sets out the standard sort of cables: PVC or rubber-insulated, impregnated paper, mineral-insulated copper-sheathed, etc.

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.

Trumpy, I like the NZ Twin and Earth, stranded is so much easier to deal with in sizes over 1mm sq.

The placement of the earth in the centre makes sense to me, I can see a couple of advantages,
1. If you cut into the cable your knife/saw will hit a neutral or earth first, then short to the phase, less risk of electrocution by DIY, and 2. frequently on wiring accessories the earth is the middle terminal. (ok that one's stretching it). I also like the concept of the full sized insulated earth.

T-R: I know that scheme, it's about the only international standard that ever took off to any degree

Paul,
This is quite a recent thing, the sequence used to be Red, Black, Green.
I have an idea that AS/NZS 3000:2001 calls for Twin + Earth flat cables to be like this.
It makes sense though, having the Phase conductor between the other two conductors, both of which are usually at Earth Potential.
Yes, it is plain old green, the cable in the photo was taken from an old length of cable I had lying around in my office.
Earth wires in new cables here wear the green/yellow colouring these days.
Only with cables up to 2.5mm2 do we have the Earth conductor the same size as the Phase conductor.
4mm2 has a 2.5mm2 Earth, as does 6mm2.
Chipmunk,
Our TPS cable is really easy to strip too, mainly because the sheathing is a bit softer than it used to be.
However,
This can also translate into cables being damaged easily by rough handling and of course, rodents.
Just a little side question, do you guys have an easy way of keeping 1mm2 2C+E flat when installing it?.
I've never been able to keep the cable runs of that stuff nice and neat and flat. GRRR
The insulation always ends up all lumpy and twisted looking.
It may be the reason why I prefer to use 1.5mm for all but the lowest current jobs.
Anyone have any ideas?