The Frustrations of Electricity Around the Globe

Thanks for putting this up. I'll look at the referenced links to see if I see a picture of a ring main. I've never seen one.

Not only is it aggravating it's bad for business also. I once had to connect telephone cable (Euro) with US made cable that we got just because the Iron Curtain fell and no Euro cable was for sale. What a nightmare, the cable comes in pairs of 3 while euro cable comes in pair of 4. Once the supply issue was solved we jumped back to purchasing euro style cables as that was 99 % of our network. All US business was avoided just because of this mismatch. Business that could have been ours went overseas because we can't get our head around the metric system. If the economy looks blurry now, well think what it will look like in a couple of years. The Chinese don't care what system we use. They'll make it and to anyones specs.

Why is that so hard for American manufacturing....

I have been seeing a lot of newer electronic equipment being labeled, "95-240 V AC, 50-60 Hz" suggesting that at least someone in China is aware of this issue...I am still waiting for the first motor to meet these specs...

Compatibility is always an issue...don't get me started on HDTV, Vido players and phone charger...
Oh, yes ...phone chargers are to have a common standard plug, due to come in when hell freezes over.
Del

Thanks for posting this and hopefully having something click with manufacturers and specifying engineers

Though becoming rare, I still find confusion occasionally when I am called to witness a FAT or review design documents.

I have seen equipment designed for 50Hz trying to be tested with some 60 Hz equipment and I question this always.

Am I being unrealistic, as I have been told, our am I questioning a test that may not meet the parameters of design considerations?

Running 50Hz transformers and rectifiers from 60Hz supplies is generally OK - so long as there is nothing in the load that utilises the supply frequency. 60Hz equipment on 50Hz supplies can be another matter - it takes more core material for a given power at 50Hz, and diode-capacitor rectifiers can start to hum. Even systems using inverter-based voltage transformers may not be immune to the second problem.

Thoroughly agree on all these points, but there is a reason in all this madness. Incompatible electrical supplies make big corporations sleep well at night, at the thought of selling you the same product allover again.

"Oh my gosh" says Big Products R Us CEO Ivor Belly. "We have sold our customers everything they need!"

"But ve have zee cunning plan." says Big Products R Us Marketing Dept Head Slime E. Ratt. "Ve note that all ze voltages are veeery different. Ve vill make ze products incompatible and force ze customers to buy new kit!"

"It will never work!" says Ivor. "Our customers are too smart! They will see through such obvious trickery!"

"No!" says Slime. "Ve vill make only the slightest of changes! Zen ve vill design a non-standard cable vith vitch to connect to ze electricity! Ve vill charge 10's of times more vor zis cable than z product! They will be conned vor sure!"

"Make it zo!" says Ivor, who succumbs to the accent also.

I campaigned long and hard for the UK to rid itself of the ridiculous and dangerous ring system. Hasn't happened yet.

By the by, the DC link between France and UK is not DC because the mains are synched, but becuase it has to be for an undersea cable to work efficiently.

"ridiculous and dangerous ring system"

I don't suppose that you are comparing with one cable per socket, as this really is ridiculously expensive, both in terms of wire routing difficulty and cable cost.

So it must be a comparison against pure-radial systems?

The ring relies precisely on the same diversity that makes multi-outlet radial systems possible. It is effectively two spurs with the ends joined. Where the target area is small it can allow reduction of copper usage compared with alternatives and easier routing; this is due to the same "diversity" that makes multi-outlet spurs possible. Note that there is minimal or no advantage if either the target area or the distance to the target area is large.

In spite of the theoretical risks, the incidence of ring-induced events is very small. This is at least in part due to the de-rating of the system to allow for asymmetric loading. Nevertheless, I would support proposals for a modified standard for the ring main for future installations. The modification would be to treat the two ends of ring as separate circuits, each to include low-sensitivity (perhaps a sense-current of about 0.5-Amp) RCDs. The advantages of such a system are both that it would allow fuller exploitation of the cable capacity, and also that it would minimise the stray field that broken and high-resistance links might cause.

Of course, other than providing the appropriate fused plug, this has no impact on the "global frustration" issue. Individually fused plugs or sockets should of course be mandatory in any system where the distribution fuse exceeds the individual device rating. I find their absence in some jurisdictions to be of far greater concern, given that this has demonstrably caused far more and more serious adverse events than problems with incorrectly-installed or damaged rings.