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#217186 - 05/27/16 03:59 PM Re: Mains supply in GDR [Re: annemarie1]  
annemarie1  Offline
Member
Joined: Mar 2015
Posts: 54
england
I have come across double pole fusing here once or twice I was told by an old electrician that they were from an old DC supply but had just been used when it was changed to AC I suppose it's possible that a few places in the UK had ,127/220 volt supply's I know central London had a 110 0 110 volt system it was AC I don't know the frequency.


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#217191 - 05/28/16 12:31 PM Re: Mains supply in GDR [Re: annemarie1]  
Texas_Ranger  Offline
Member
Joined: Dec 2001
Posts: 2,397
Vienna, Austria
I've heard the DC explanation too but since all our DC systems had an earthed centre conductor it doesn't make that much sense.


#217208 - 06/02/16 08:29 AM Re: Mains supply in GDR [Re: annemarie1]  
geoff in UK  Offline
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Joined: Dec 2002
Posts: 183
UK
I know we've drifter away from GDR, but there is an interesting discussion on some historic UK systems here: http://www.theiet.org/forums/Forum/messageview.cfm?catid=205&threadid=24408


#217209 - 06/02/16 06:09 PM Re: Mains supply in GDR [Re: annemarie1]  
annemarie1  Offline
Member
Joined: Mar 2015
Posts: 54
england
Thanks for that it was a fascinating read


#217211 - 06/03/16 05:22 PM Re: Mains supply in GDR [Re: annemarie1]  
Texas_Ranger  Offline
Member
Joined: Dec 2001
Posts: 2,397
Vienna, Austria
I just found an old textbook from Austria that clearly states that in TT single-phase circuits it was still perfectly acceptable to fuse the neutral by 1972! The book also points out that fusing the neutral of a 3-phase supply or worse the PEN is a super-bad idea.

That explains the large number of fused neutrals in Vienna and the surrounding areas I'd say. Not sure when fused neutrals were eventually banned but my guess would be mid-80s or maybe even early 90s. In theory you're supposed to replace the neutral fuse with a solid link whenever you work on such an installation but nobody ever does - either nothing at all or the entire consumer unit is replaced. When we had our meter moved in 2003 the electrician connected the new supply to the old main fuses without as much as blinking so we still have a fused neutral ahead of the meter.

I do know people who got bit because they only unscrewed the neutral fuse, saw that the lights went out and thought the circuit was dead. Especially since very very few people bothered to label any fuses back in the day.


#218545 - 06/15/17 04:02 PM Re: Mains supply in GDR [Re: annemarie1]  
dsk  Offline
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Joined: Jun 2014
Posts: 59
Norway
I wake this old thread. As far as I know Germany was pretty standardized to 220/380V Y 3-phase even before WWii.

An the other hand local standards has been surviving surprisingly many years.

Here in Norway we still have 230V 3-phase with no neutral. 3 wires with 230 V between and measured about 127 to ground until the first failure. Sometimes this results in a grounded phase and 230V between ground and the 2 others. On these systems we use 2 fuses, or more recent dual circuit breakers.
Where we have 230/400V (newer) with a grounded center of the Y we still use double breakers, but not fuses. You shall not be able to switch off neutral without switching off live wires. This mix of systems makes the color-code of neutral wire confusing, because we use the same rolls of cables. Where Neutral is, it shall be blue, but when you have no neutral blue might be live wire. Actually no problem, always treat a wire as live!

Some of the very first 230V systems with neutral had fuses, but not on neutral. They even tried to use common neutral and ground to the receptacle, this is not by code anymore.

dsk


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