Several days ago I came to an old Villa in Vienna soon to be demolished (In fact demolition started yesterday, so nothing of this is left) looking for oak floors. I got permission to take whatever I want, but the floors were rotten. So I only took some vintage light switches (replicas as I found out later) The main fuse box ahead of the meter was open. It contained two rows of fuses ( in those panels phases/neutrals are gathered in vertical rows, so the line terminals can be linked with brass straps) The upper row contained two 32A fuses and an unfused neutral, the bottom row a single 32 A fuse not linked to the upper ones at all and 2 independent 10A fuses. On the panel door it was printed 220V and 440V. Obviously this was a supply similar to American ones, that had been later converted to standard 220/380 3 ph by hacking in a 3rd phase. No one I asked has ever heard of this!
My guess would be that the original service was 220/440V 3-wire DC. Many early supply systems were DC, and this being Vienna it's quite probable that electricity was introduced into the district fairly early on. Many older parts of British cities had DC supplies that continued until well into the 1950s.
It could have been 1-phase 3-wire AC, but I think these systems were rare to non-existent on this side of the Atlantic. I don't know whether Austria could have been an exception, but I'd place my bet on DC.
[This message has been edited by pauluk (edited 08-22-2002).]
Re: 220/440V 2ph/3w service in Austria#133555 08/23/0204:50 AM08/23/0204:50 AM
Finally got a reply. It was a +220/-220/0V DC system, converted to 3ph AC around 1950. BTW the janitor's appartment (kitchen, 1BR) had 10 A MAIN FUSES! Not much juice! maybe less risk of electric pouring out of our receptacles with their big holes...
Re: 220/440V 2ph/3w service in Austria#133557 09/05/0202:06 PM09/05/0202:06 PM
Could cause a problem for the average Brit who is firmly attached to his trusty electric kettle.
C-H, I heard that some parts of Scandinavia used a 220V system operating from a xfmr which was center-tapped to ground so that each leg was only 110V to earth (i.e. similar to the American 120/240V 3-wire system but without the neutral extended to the house).
Do you know if any such arrangement existed (or indeed still exists) in Sweden?
Re: 220/440V 2ph/3w service in Austria#133560 09/20/0209:06 AM09/20/0209:06 AM
I heard that some parts of Scandinavia used a 220V system operating from a xfmr which was center-tapped to ground so that each leg was only 110V to earth (i.e. similar to the American 120/240V 3-wire system but without the neutral extended to the house).
In the 1950's there were three systems in use: 110V, 127V and 220V. (DC was also used in some places.) I'm too young to know when these were converted to 220V only.
The system you describe is rather uncommon these days, but I worked in an office a few years ago where every room had a blue CEE 17-socket with this system. The rooms had been used as labs (or something similar) previously, so I suppose it was a safety feature. (The wiring was rather new, with a consumer unit with RCD:s and MCB:s in every room)
Also, a small number (perhaps single digit) of buildings with their own transformer still use this system for general purpose sockets. In some cases a 127/220V system (3-phase) is used for safety reasons. (I've seen it in labs with their own transformer.)
However, I would guess that 99.9% of the houses are supplied with the standard 230/400V.
Re: 220/440V 2ph/3w service in Austria#133561 09/20/0211:02 AM09/20/0211:02 AM
4A fuses? They've been discontinued here in Austria years ago, replaced by 6A ones that also have been discontinued or at least aren't sold in bigger hardware stores any more. Smallest fuse size commonly available is 10A. 16A for higher rated residential circuits, 20 and 25A for main fuses. Do you fuse the neutral in sweden as it is done here?
Re: 220/440V 2ph/3w service in Austria#133562 09/20/0202:18 PM09/20/0202:18 PM
Thanks C-H. I hadn't realized that 127/220V 3-phase was also used in Sweden, although I know it was employed in some other parts of Europe, e.g. France and Spain.
I've seen references which indicate that some areas of Norway actually employ an non-earthed 230/400V distribution system. Has any such arrangement ever been used in Sweden too? The electrical regulations in the U.K. have specified that all public supplies must have one pole solidly earthed since at least the 1930s.