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Meadow #213757 07/08/14 06:33 AM
Joined: Jun 2014
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dsk Offline
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Thank you for this explanation. You are right in hence of my reference was to a rotary dial telephone. The rest was all new for me, and yes it differs great from what I believed was right. My mothers thounge are Norwegian so please forgive language problems.

dsk

Meadow #213939 09/10/14 05:51 AM
Joined: Sep 2011
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Meadow Offline OP
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Thanks for the info! laugh smile From what I gathered thus far, the Norwegian transformers are 230 volts ungrounded wye on the secondary and grounded through a "nullpunktsikring" http://www.el-tjeneste.no/files/Brosjyre-Nullpunktsikring.pdf

Basically its just a surge arrester with a fuse. If a surge occurs such as a primary going into the secondary, the arrestor shorts the transformer neutral to ground by blowing the internal fuse. Under normal conditions it remains isolated from ground. 230 volts is present between phases and no neutral exists for loads like in a 230/400Y network.




Meadow #213940 09/10/14 06:10 AM
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Meadow Offline OP
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Here are some photos you might be interested in:

https://s855.photobucket.com/user/mbrooke22/library/?view=recent&page=1

Meadow #213943 09/10/14 03:18 PM
Joined: Apr 2002
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Gardner:
Interesting photos, although most are out of my expertise.


John
Joined: Sep 2011
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Meadow Offline OP
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Thanks!

They are off the net, and appear to be from Norway. Neat to say that least, very different than what we find in the US. Cool stuff grin

Last edited by gardner; 09/11/14 01:45 AM.
Meadow #213952 09/12/14 04:55 AM
Joined: Jun 2014
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dsk Offline
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Definitly a difference.

Norway are following the EU in the way of this.

The main difference are the tradition of systems with
NO NEUTRAL This has implemented fuses in all wires, and when breaker became the rule, they are now sensing, and breaking all wires simultaneously, even neutral where those are. It is more and more focus on covers, and it shall not be possible to touch any wires or terminals without removing a cover (This makes even measuring a little more heavy, and you may often find missing covers to be replaced later by "lazy" workers".

You are not allowed to rewire your own home here, its extremely limited what you may do legally in your own house. It is common to have a main switch or breaker in all cabinets, something I have been missing in US homes.

Another difference may be the extremely long distances from the transformer to the consumer. On the countryside it may be several 1000 meters (~yds). This may cause considerable voltage drops, and instant water heaters are "unofficially banned".

dsk

Meadow #213953 09/12/14 05:25 AM
Joined: Jun 2014
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dsk Offline
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This is not the common Norwegian standard water heater state of service, but a
scary one:
[Linked Image from electrical-photos.com]
[Linked Image from electrical-photos.com]
[Linked Image from electrical-photos.com]

Last edited by dsk; 09/12/14 05:29 AM.
dsk #213954 09/12/14 05:55 AM
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Meadow Offline OP
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Originally Posted by dsk
Definitly a difference.

Norway are following the EU in the way of this.

The main difference are the tradition of systems with
NO NEUTRAL This has implemented fuses in all wires, and when breaker became the rule, they are now sensing, and breaking all wires simultaneously, even neutral where those are. It is more and more focus on covers, and it shall not be possible to touch any wires or terminals without removing a cover (This makes even measuring a little more heavy, and you may often find missing covers to be replaced later by "lazy" workers".

You are not allowed to rewire your own home here, its extremely limited what you may do legally in your own house. It is common to have a main switch or breaker in all cabinets, something I have been missing in US homes.

Another difference may be the extremely long distances from the transformer to the consumer. On the countryside it may be several 1000 meters (~yds). This may cause considerable voltage drops, and instant water heaters are "unofficially banned".

dsk


Do they have a home supply center in Norway? What happens if someone re-wires their home without permission? I guess Im just really curios.

In America people can go to a 'Home Depot' or 'Lowes' and buy everything they need to rewire a home: electrical panel, wire, boxes, outlets, meter sockets, ect no questions asked. Sometimes in some areas a person should pull a permit and let the town know that is happening, but, being honest that usually doesn't happen. In America the average home owner can re-wire his entire home and not be punished.

In US home you are required to have a main disconnect either outside or the panel right after the meter. But sub panels are not required to have this disconnect. However, a detached structure from the home like a shed or garage must have a main disconnect or less than 6 breakers to turn off all the power to the structure.

How much is the average voltage drop? Does 230 volts drop to 210 volts? Also why the ban on instant water heaters?

One more question: In Norway, do all IT systems not interconnect the grounding systems of different structures? In that only 2 or 3 hots, no ground to a home?

In systems where ground/ earth wires (jord cable) do not interconnect all structures that can be a major fire risk?

(In one home phase "A" may ground to the case of a fridge. Ok, just a TT system now. But if phase "B" grounds in a home two from the same transformer in the electric heater and the grounding system of the 2 homes is not interconnected home one and home two will have ground grids of opposite potential. The 230 volt potential will make power flow across the earth creating voltage gradients and heating up the grounding system drying out the soil)

Meadow #213955 09/12/14 05:58 AM
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Meadow Offline OP
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Here is what I found of the typical system:

Attached Images
1183453-9-1332769451496.jpg
Meadow #213956 09/12/14 05:59 AM
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Meadow Offline OP
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One more:

Attached Images
MGp3enJk.jpg
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