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Posted By: Hutch South African Light Switches - 07/25/02 03:15 AM
This is somewhat of an experiment as I've never attempted before to post pictures to a list - but here goes.

[Linked Image from members.aol.com]

I don't know about elsewhere in the world but there are some nice features regarding South African light switches when it comes to wiring them ganged up in multiple that I have not come across on UK or USA versions.



Firstly like UK switches the connections are compression types with a grub or short screw (M3.5) holding down solid or stranded wire in a hole large enough to take two or three wires if necessary for joining purposes - no wire nuts required.

A single switch is pictured but they can be ganged up to four side by side in the appropriate fitting and still fit in a 2” x 4” box. Yes, the metric RSA switches and plugs are the same size and have mounting holes that line up exactly with American boxes! So there is a world standard!

Single switches are mounted vertically as in this example. Pairs of switches can be mounted vertically or horizontally, usually vertically – the switch’s short axis is exactly half their long axis. Groups of threes and fours are stacked vertically with their long axes lying flat.

[Linked Image from members.aol.com]

Secondly, the terminal used as the feed is in the center of the unit which is an important element of their design. When ganged, the feed holes of the various switches line-up and one wire, suitably striped, can be inserted through all of the switches and clamped by each switch without any further junctions being required. The load terminal(s) is/are on the outer edges of the switch – a 1 way switch is pictured.

[Linked Image from members.aol.com]



This feature makes for very easy wiring of light switches which I miss on USA fittings.

BTW, most residential work in South Africa uses wire in plastic conduit. Romex equivalent has a thin aluminium sheathing under the outer white plastic coating and can be used exposed, i.e. pinned directly on the inside of a garage/workshop wall. UV grade cable is available for exposed outdoor use – it was not to be buried without additional protection in conduit etc. I’ll post some pictures of this cable at a later date if this posting works.

Edited thrice due to severe dyslexia!

[This message has been edited by Hutch (edited 07-25-2002).]

[This message has been edited by Hutch (edited 07-25-2002).]

[This message has been edited by Hutch (edited 07-25-2002).]
Posted By: pauluk Re: South African Light Switches - 07/26/02 07:26 PM
Glad you got it working!

The feed-thru terminal to bring power into multiple swithes on one wire is a neat idea. I'm sure you'll remember the task of linking one terminal to the next on British multiple-gang switches.

I'm assuming from the red marker on the rocker that South African switches follow the British convention of down for on, right?

Do you know if it's still possible to buy toggle switches in the R.S.A., or have they gone to all rocker switches as here?
Posted By: Hutch Re: South African Light Switches - 07/27/02 01:52 AM
That is correct, Paul. RSA drives on the on-is-down side of the road for light switches but CB's work on the on-is-up principle.

As to your other question, I have only seen rocker switches in RSA and no toggles. The older pattern of rockers emerged through individual holes in the face plate whereas the newer ones pictured above abut each other when ganged, and fill a common hole in the face plate. When ganged horizonatlly (up to a stack of four) the switches are fitted to a common base plate, not visable in my pictures above. The mounting holes are drilled half a switch width apart to allow the ganged switch assembly to be centred irrespective of there being an odd or even number of units in the stack. To add a switch, all one does is reposition the existing switches by half a unit, add an extra one and change the face plate.

[This message has been edited by Hutch (edited 07-26-2002).]

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Posted By: Hutch Re: South African Light Switches - 07/28/02 09:27 PM
Further to my posting above I mentioned the type of cable that could be surface mounted in say garage or workshop. It’s nice to work with as it is quite capable of tight bending yet the inner aluminium sheath gives it a degree of rigidity that allows it to retain its form after bending. Plastic glands are used to guide (and protect) the cable into steel or plastic fittings for mounting switches or receptacles. It's called "Surfex". Common sizes are 2.5 sq.mm for power circuits up to 20A and 1.5 sq.mm for lighting circuits up to 10A. The larger size is pictured below.

[Linked Image from elkonv.com]

The fake/packer wire is solid PVC (sometimes clear or light tan) and is used to keep the overall cross-section of the cable round. It is not required in 3 + Earth varieties where the insulated wires are coloured red, white and blue, i.e. no “defined” neutral (black) for use as commons in two-way applications etc. There is no paper or other fabric used in its construction. In South Africa I never came across the use of paper in cables and the only fabric I ever saw used was in older heat resistant appliance cords such as fitted to toasters and kettles.


[This message has been edited by Hutch (edited 07-28-2002).]

[This message has been edited by Hutch (edited 07-28-2002).]
Posted By: pauluk Re: South African Light Switches - 07/28/02 09:57 PM
Rocker switches are the norm in the U.K. now. In fact, the manufacturers seem to have stopped making toggles altogether, except for some over-priced mock-Edwardian/Georgian style brass fittings.

I think North America is probably the last bastion of traditional-style toggle light switches. Personally, I prefer toggles.

That's an interesting style of cable. Round types such as that are available here, but the regular NM-style cable is just an oval-shaped PVC sheath containing the conductors laid in a flat configuration (I know you'll know that Ian; I'm just including it for everyone else).

Are you sure that the RSA is still using 3-core cables with red, white, and blue? British 3-core cables changed to red, yellow, blue in 1965 when the phase B color was changed from white to yellow. (There are still plenty of the older cables in use, of course.)

When I need a neutral using the 3-core cable I generally use the blue (taped black at the ends to identify it). If the other two wires are permanent hot and switch return, then I'll keep the red as the former and use the yellow (or white) as the latter. That seems to be the most logical to me.

When using the 3-core for 2-way (U.S. 3-way) switching, then for the traditional method I use the yellow and blue as travelers and keep red for power in & feed to light.
Posted By: Hutch Re: South African Light Switches - 07/28/02 10:32 PM
Yes Paul - Red, white and blue!

[Linked Image from elkonv.com]

The 3 phase feed coming into our housing complex was the same group of colours with each meter in turn receiving either a red, white or blue feed.

Major substations have their insulator poles coloured the same according to phase.

[This message has been edited by Hutch (edited 07-28-2002).]
Posted By: pauluk Re: South African Light Switches - 07/30/02 08:48 AM
Hmm... I guess that when the U.K. changed the B-phase color to yellow the RSA decided to stick with white for whatever reason. I've never actually been able to track down a reasonable explanation of why we changed.

The standard socket in the RSA is still the BS546-style 15A (round-pin) outlet, right? Are these also fitted on a plate the same size and shape as the light switches?
Posted By: Hutch Re: South African Light Switches - 07/31/02 07:47 PM
They can be fitted to the same sized boxes as the light switches but usually in landscape mode rather than portrait as with the unit pictured below.

[Linked Image from elkonv.com]

More usual are the larger 4x4 square units that contain either a single or pair of sockets. A single unit is pictured below. Incidentally, this unit is missing its shutter mechanism which broke and the holes are wide open – that’s why its in the glory box and not in an RSA wall.

[Linked Image from elkonv.com]

When mounted as a pair in a 4x4 plate, they are mounted sideways with the switch still next to the live pin but with the two earth pins facing each other. That’s probably as clear as mud but I do not have an example to hand. The live pin would therefore be the highest on one of the pair and this parallels the debate currently active on the USA forum re receptacle orientations

Searching for an example, I came across a new arrangement on the Crabtree website http://www.crabtree.co.za which is a 2x4 in portrait mode which I’ve never seen before. The switch is at the top above the earth pin rather than next to the live pin, which looks quite odd to my eyes.

[Linked Image from crabtree.co.za]

Hope this helps.


[This message has been edited by Hutch (edited 07-31-2002).]
Posted By: pauluk Re: South African Light Switches - 08/01/02 11:53 AM
Interesting -- I'll go back to the RSA Crabtree site for a better look when I get the time. I notice that they've increased the rating of the outlets to 16A now, not that these old plugs and sockets would have any problem handling that. I've always felt that our old connectors were very conservatively rated -- The good quality 15A types would probably carry 30A without any trouble!

I've come across one British outlet with a switch fitted horizontally above the socket, but that was the smaller 5A style (I can't remember what make it was).

One question that comes to mind about the RSA double outlets oriented sideways: Are the plugs all still the right-angle type like British ones?
Posted By: Hutch Re: South African Light Switches - 08/01/02 07:06 PM
It is interesting that you point out that the sockets are rated for 16A rather than 15A –I hadn’t noticed that before. I’ve just checked through my box of South African plugs – I got an awful lot for some reason! – and the old ones say 250V/15A and the newer ones (say < 10 yrs) are marked 250V/16A. I have no answer as to why or when the re-rating occurred but one may be able to chase it down through the SABS.

BTW my brother-in-law’s ~20 year old house in Scotland has an 15A old style plug and cord serving as a disconnect for his immersion heater in a closet. Is this normal? I have no idea what amperage the circuit was rated as I never looked, but the heater looked full sized and I would have thought that such items were on 25A circuits or larger. Can those plugs be used for loads greater than 15A ? – I know that by law now any residential – non-lighting - outlet rated 13A or less must use the square pin, fused variety.

You mentioned the cord angle. All cords out of all RSA plugs 5A or 15(16)A come out the bottom of the plug between the live an neutral pin and flush with the wall. Obviously with the socket mounted sideways, the cord comes out of the assembly sideways but as it is still flush with the wall, it is not that untidy.

I have only recently come across a fit-it-yourself right-angle plug for here in the States made by Eagle. The varied orientations of US receptacles are neatly circumvented in its design by allowing the 3 pin sub-unit to be fixed at any of eight different angles with respect to where the cord emerges. The only example I found so far was 240V/20A and bright yellow but I’m hoping to stumble across some white 120V/15A examples and tidy up my kitchen counter.

Before I ventured far out of the UK and RSA, I had never come across plugs where the cord emerged straight out of the back. The instructions on electrical appliances that stated, “do not remove the plug from the socket by pulling on the cord” baffled me entirely as it was obviously impossible!
Posted By: pauluk Re: South African Light Switches - 08/02/02 12:44 PM
My guess would be that South Africa has uprated them to 16A to line up with the emerging common European standard (the "Schuko" plug common throughout the Continent is rated 16A).

As I have mentioned in another thread, our standard 5, 15 and 30A circuit-breakers have been changed to 6, 16 and 32A in line with this.

The 15A round-pin plug is considered obsolete by the technical committees here, so they probably saw no need to change it, but as it's still the current standard in the RSA I guess they decided to change the rating.

What's SABS? South African British Standards???

On the immersion heater, just about all U.K. domestic types are rated 3kW and run on a 15A (or 16A these days!) branch circuit -- 3000/240 = 12.5 amps.

I've seen many installations dating from around the 1950s where the heater was plug-&-cord connected, but it's rare to find it in a house only 20 years old. As far as the "Regs" go, it's fine so long as the outlet supplying the heater is on its own dedicated circuit and not wired into a general-purpose ring. (A small oversink heater can be on the ring, but a 3kW immersion heater is considered a continuous load and needs its own circuit.)

The only possible problem I can see with the plug-&-cord arrangement would be if the cylinder is located in the ubiquitous airing cupboard with its access door inside the bathroom. You could then get into an argument as to whether it violates the rule about no sockets in a bathroom, and whether being inside the cupboard constitutes being inside the bathroom or not.

The most common problem I see with immersion heater wiring is where somebody has just run the "twin & earth" (NM-style cable) straight into the heater, instead of changing to heat-resistant flex for the final connection.

Quote

I know that by law now any residential – non-lighting - outlet rated 13A or less must use the square pin, fused variety.

I'm not aware of any such law, although the rate new rules are being introduced these days I wouldn't be surprised!

But even if the IEE Regs. stopped recognizing the old-style BS546 outlets, that in itself would not make it illegal to install them because there is no legal requirement to follow the Regs. in domestic installations.

Note that this is England & Wales. As I'm sure you're aware, Scottish law sometimes differs from that here and I know that for many years the Scottish Building Regulations have specified that electrical installations must be in accordance with IEE Regs. Whether they have also added any other specific requirements, I don't know. (Strange, but although I've been halfway across America and around Western Europe, I've never been to Scotland!)
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