ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades Recessed socket outlets - but clean and no dust!

We had quite a lengthy discussion on the subject of 230/240V kitchen appliances in the US a few months ago I think and I was referring to that thread. Some posters jokingly indicated such practices were going to become more and more common and I just continued down that path

It might happen - many European countries once used 127V three phase distribution. Over the years, more and more appliances were connected phase to phase and eventually the power companies stopped providing 127V altogether. The same thing might happen if 240V 15 amp receptacles in the US become widespread enough and the chinese manufacturers decide to import only 230V gear any more.

There's a bit of a difference though.

In Europe the 127V split phase systems were very much in the minority. 220V 50Hz phase-to-neutral systems were far more common place and became the absolute norm after WWII.

For example, in Ireland 220V phase-to-neutral was standardised upon before 1923. From what I gather, it was also the norm in quite a lot of other countries too.

Because the 127V systems were only in certain areas, appliance makers didn't bother catering for it.

Before long, nobody made 127V appliances or light bulbs, so systems were all wired to provide 220V.

Does anyone know what type of plugs and sockets were used with the old 127V systems? Were they any different from Schuko ?

Obviously there must have been quite a few different types around as there was no European standards at that stage.

I travelled around Europe a lot in the 60's mostly by thumb and seem to recall 127v in Paris, Luxembourg and Leningrad. The sockets were all 2 pin same spacing and same thickness as current CEE 7/16 plugs. I carried a homemade adapter consisting of a European 2 pin plug and UK BS546 2 pin socket for my shaver. The European plug had quite a thick case which stops it fitting in modern Schulko sockets.

The 127v circuit is pretty rare now due most are pretty much updated now.

However there is few spots still using it on old transfomer connection I know few area used that but now everything is wired for 415Y240v format

Merci,Marc

As to the town I live in I have understood the development as follows:
In the inner city, the first what was installed was DC starting at about 1900.
In the 20ies AC came up in the form of 220/127 3 phase. It would reach the outer circle of the town.

After WW 2 new installations were all in 380/220V. A house would always have a 3 phase service but usually 1 phase counters. With the introduction of electric cooking 3 phase became standard on the houshold level. So some areas in the outskirts would have this system as the first installation. Unfortunately often 2/4 wires with PEN until 1971.

Now DC installations were usually upgraded latest after WW 2 to 380/220 2/4 wire systems. DC systems were ungrounded, so this was the easy way to upgrade without rewiring. I hate those as every wire has the same color.

220/127 were first upgraded in the way that only 220V were used which has the advantage that these houses although pretty old have a 3/5 wire basis which often can be reused still today. Transformers were changed to 380/220 beginning of 1960. Some are still left (2 in my city). The one I live with is privately owned.

Change to 400/230 was done on the 10/20kV level.

In near Belgium the rural area around Eupen f.i. there 400/230 was introduced just some years ago. 230/133 is still the standard installation.

I was told by several German electricians that 127V line to neutral was still quite common around WWII and 127V light bulbs were readily available.
Radios had 110, 127, 150, 220 and 240V settings well into the 1960s.

127V Schuko plugs had really weird pins that weren't round but concave on both sides (looking at a socket with the holes aligned horizontally). This was made to prevent 127V appliances getting 220V but not the other way round. Other than that they were built like 220V Schuko plugs.

I suppose ungrounded round plugs were used for 127V too.

Indeed, most city centers first got DC in the late 19th century and the outskirts, especially commercial and industrial neighborhoods got 127/220V AC for the operation of three phase motors in the early 20th century. In Vienna, the 3 wire DC services were mainly converted to 127/220V w/o neutral since the old wires could be reused - 220/380V would have required a fourth wire. The last DC service (residential) was converted in 1955. The last 220V three phase systems (PoCo transformers) were phased out in the 1970s I think, some private transformers lasted much longer, one was replaced in 1989, some might still be in operation, though I doubt it.

Addis Ababa, Ethiopia still uses 127V 3 phase. I was watching a hotel sparkie picking up voltage on both sides of an italian style socket. We got chatting and he confirmed the type of supply.

As do some areas of Berlin (nominal 133/230V). I even heard rumors of 115/230V 1 phase 3 wire systems in use in Germany(outside US army facilities).