South African Low Voltage Distribution Network Configuration?

The random in the UK is not really random.

In my suburb in South Africa we also attempt to keep the phases in balance by "randomly" subdivide the area in blocks / streets which are then connected to the same phase.

Nobody are allowed to connect the next house to your connection therefore having power available next door serves no purpose.

In the informal housing sector the people break the distribution box and randomly connect to any phases.

mmm, the random in the UK is indeed not really random, it has more to do with the construction of the cable, eg. waveforem cables. Jointers just tend to connect to the most accessible phase, when connecting houses. I should point out that I am referring to underground networks in the UK.

In South Africa I am referring to overhead networks, am i right in thinking that neighbours in South Africa, if connecetd to the network, are all connecetd to the same phase and only one phase will generally supply one street for example?

Hendrik just re read your post and you have already answered my question, so thank you for the information! I find it facinating how similar transmission networks and distribution networks are internationally, but when it comes to low voltage networks they are often very different!

Many distribution systems in SA grew from 100 volt DC into 220/380 volt 3 phase overhead system (and beyond). Many small towns and even bigger towns like Kimberly had 100volt DC.

The town where I grew up converted in 1955 (when the power station burned down) but was not connected to the national grid at that stage.

I don't think they at first replaced the cables and we did not have the option of 3 phases available at each property.

The Diamond City, Kimberley, switched on electric streetlights in 1882 making it the first city in Africa to be illuminated in this manner. At this time, London still relied on gas lamps for street lighting.

Between 1884 and 1890 the use of electric motors, lights in mines, private lighting and an electric tram evolved. The first central power station was established in 1891.

The discovery of gold on the Witwatersrand in 1886 led to Johannesburg installing its first electric lighting plant in 1889. This electrical power was generated by gas engines. An electricity reticulation system followed in 1891. Municipal electricity supplies started in Rondebosch in 1892, Cape Town city centre in 1895, Durban in 1897, Pietermaritzburg in 1898, East London in 1899, Bloemfontein and Kimberley in 1900, and Port Elizabeth in 1906.

I think you'll find the UK uses anything but a random division of feeds to properties. They are planed to balance the system. As to breaking in to a wavecon cable you can get the any phase easily. The jointer connects to the phase he is told to, not which he feels like or easiest. Much of the system still uses PILC. The various radials from a substation can be interconnected via underground link boxes or link pillars.

I don't know where you're getting your research information from, but I'd find another source.

I used the term random as shorthand as if it was truly random, it would tend toward the balanced condition.

It has been uncovered that significant current unbalance is present on UK LV feeders through detailed monitoring trials in recent years. There are perceived to be multiple causes for this, one of which is the human element, another is the natural evolution of homes, I did not intend to single out jointers as the cause, but now realise after reading my hastily put together post, that is pretty much what I said, but it is not what I meant. Sorry about that, I would just like to set the record straight here, all jointers I have observed working in the UK maintain impeccable quality standards and I have found them to be true craftsman.

Read this

http://www.eon-uk.com/downloads/network_design_manual.pdf