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Old 25th July 2010, 06:08 PM   #21
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Hi, I am living in a small country that is for the most part meters under sealevel and still cabling is nearly all under ground in a wet environment. Please don't take my comment as nationalistic but despite our size (or maybe because our size) our infrastructure is of a high level because of a profound investment in it in the past. Just as the water system, the natural gas system and the telephone/internet system. Of course we find enough reasons to complain about other things like the outrageous taxes here that finance these projects. But these things come when living under sealevel.

Very little to no blackouts even with the cabling in the ground. In the area where I live we only experienced a blackout some years ago when a military helicopter flew in a 100 meter high 50 kV air cable at night. The cable fell in a river which looked as a big fireworks to people passing by. Pretty spectacular and one week no power. I mostly experience blackouts when I am abroad to be honest.

I used to work for a power company a long time ago and then I helped removing some of the old poles that were used for power distribution 40 to 50 years ago. There are almost no pole mounted transformers here for safety and reliability reasons. Also cabling is of very high and expensive local made quality with a lot of features to protect it from moist, damage etc. Depending in the situation they are also laid in pipes to protect them and cabling is laid in "rings" so transformers can be fed from 2 directions. Also the transformers that are locally made rarely fail. If they do it is mostly due to structural overloads or lightning strikes. In my job at a datacentre of 4 MW I only experienced some dips and some peaks in three years time and this is in the most power hungry part of the country with the highest risks for outage. I decided a few times to switch over to our diesel generators only to avoid the UPSes from being drained. The only times our generators and UPSes were really needed was when we tested them live every month.

But unfortunately power companies that were previously owned by the state have been privatized because of EU rules and now maintenance level is degrading. Years ago it was their duty to provide electricity for the people at cost. It was also one of the minimum features for wellbeing so power was seldom cut off if someone did not pay his/her power bills. Today profits are more important. Some time ago a TV ad was broadcasted telling us to prepare an emergency set with candles, a flashlight etc, because the things we are used to might fail in the future...

There is no "best" but "good" is enough....
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Last edited by jean-paul; 25th July 2010 at 06:33 PM.
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Old 25th July 2010, 08:54 PM   #22
tinitus is offline tinitus  Europe
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simple things becomes complicated, ehh

I guess it has been like following
We have only had 2pin sockets for many years
3pin or 5pin have been used solely for washing machines, and professional work
Every installation do have 5 wires coming in

With the 2pin sockets we havent been prepared for the new world with computers etc
Thou new installations are done with earthed 3pin sockets
I suppose they think "hey, those 2pin with female earth fits nicely into old houses with the 2pin sockets
The legal and requested 3pin connector wouldnt
So, even simple coffee machines are sold everywhere with the schuko 2pin with female earth
And who cares about the missing earthing anyway

Thanks to all
This lesson have made things much clearer, or should I say even more clouded and obscure
It has certainly made my head spin

I know how to handle it now, thanks
But my neighbours still have no clew about it
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Old 25th July 2010, 09:03 PM   #23
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Pick up your duty as a law abiding citizen and fight for the right to safe and noise free electricity

Quote:
Originally Posted by tinitus View Post
So, even simple coffee machines are sold everywhere with the schuko 2pin with female earth
And who cares about the missing earthing anyway
You do !
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Last edited by jean-paul; 25th July 2010 at 09:05 PM.
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Old 25th July 2010, 09:47 PM   #24
Pano is offline Pano  United States
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Originally Posted by jean-paul View Post
The system panomaniac describes is the same here but here a 3 phase system (so 3 hot wires and a neutral) is used with ground. Between L and N there is 230V. Between the 3 phases (then called L1,L2 and L3) there is 400V.
Interesting! So you have 3 phase 400V coming into the home? Don't see that in US domestic service, just commercial. Then it's generally 208V from phase to phase. 120V to neutral. Is neutral bonded to earth, in your system?

In Paris we had several systems. One theater I worked in had so called "Bi-phase" which was actually 4 phases. Between phase pairs (AB or CD) there was 220V, and between the other phases some odd voltage that I don't remember. So similar to US domestic practice, but twice as many lines. Most homes had two hot lines, 110+110 for 220V total. No neutral. But there were still some older installation on the Left Bank that were 110V. So one hot and a neutral, though I don't know where the neutral came from. I believe I saw the last of these phased out in the 1980s. (pun intended). Main breakers were always GFI (ground fault).

Out in rural Sweden I could never figure out the wiring. We blew a fuse once which caused the light in the stair to glow dimly whenever we turned on the kitchen stove. Spooky.
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Old 25th July 2010, 09:55 PM   #25
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Hi, we have 3 phase electricity in our homes but normally only one phase is connected to different so called "groups" with separate 16A breakers and/or ground fault breakers. I dare to state that the local regulations are of a high standard (called NEN1010) that is now weakened because of weaker EU regulations that tend to overrule local regulations. In a lot of other things EU regulations are quite stringent though, sometimes even patronizing. So the Netherlands has a very strict regulation system on energy installations that maybe is somewhat more costly but has a proven safety. All details are described and I am pleased by the way these systems are regulated and carried out.

The 3 phase system was normal in the old days, then it was abandoned and since many years it is standard again. So in relatively modern homes it is not very difficult to have a 3 phase system provided that one can defend its use and the additional costs. The costs for a new 3 phase energy-meter and maybe heavier fuses are for the owner of the premises.

Neutral is bonded to safety ground/"earth"/PE.

edit: Neutral is connected to safety ground/PE. Safety ground/PE is used for bonding to all metal structures in a building/home, not the neutral connection as that would not be the idea of safety (reaction to brian oshman). Neutral or "N" is only used in wall outlets etc. and the cables are blue. Phase or "L" has the brown colour and switched cables for lamps are black. The neutral cable is never used for "grounding"/"earthing" metal structures etc. For that purpose the yellow/green PE cable is used exclusively, that one is also connected to a real grounding point (metal rod in the ground). I have to admit that some of the english words used for these items are not always very clear (to me at least).
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Old 25th July 2010, 10:04 PM   #26
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The term bonded does not mean grounded. Bonding is where all metal structure in the building such as metal beams and all metal plumbing is connected to the neutral of the service. The neutral is derived from the transformer supplying power. This is to ensure that all metal structure has the same potential so to reduce the chance of electric shock from structure and plumbing and electrical.

400V 3N 50 Hz is common in Europe.

Grounding Vs. Bonding
The Big Picture
  • What is “grounding”? What is “bonding”? What’s the difference?
Grounding and bonding is probably the most discussed issue here, aside from 210.52’s design requirements. The following is based on a solidly grounded conventional wiring system. For simplicity's sake, I will not discuss corner grounding, impedance grounding, or ungrounded systems in this post.

The terms are defined in Article 100 and 250.2 of the NEC. Section 250.4 provides the performance requirements of Article 250. Grounding is a connection to earth, and bonding is the connection of items to each other.

Bonding is crucial inside a structure, because without it, if something goes wrong and an ungrounded conductor comes in contact with a piece of metal that someone can touch, that someone will receive a shock and potentially be electrocuted due to the uncleared fault. A quick and dirty definition for bonding is connecting electrical devices together in the attempt to trip a breaker, if an ungrounded conductor touches surface metal associated with the system.

What does the earth have to do with this? Nothing.

Then why is it called an “Equipment Grounding Conductor (EGC)” in the NEC if it’s primary purpose is to “bond” things together? Simple answer: tradition. It’s always been called that, and the terms in the NEC have served to confuse people for a long time. Proposals have been made to change the term, and progress has been made, but the EGC continues to hold it’s misnomer.

Electricity does not seek the path of least resistance to the earth. It seeks all available paths back to it’s source, in proportion to their resistance. The reason that a person gets shocked when touching an ungrounded conductor and the earth is because the neutral of the system is repeatedly connected to earth in a grounded electrical system. The earth becomes part of a return path to the transformer – it’s part of one route back to the source; the earth is not the destination for the electricity.

Driving a ground rod to ‘ground’ any electrical equipment does not provide the low-resistance path required to trip breakers. Driving a ground rod, or using a Ufer, or a metal water pipe is not a substitute for an EGC. A ground rod with 25 ohms to earth will allow almost five amps to escape the system into the earth when directly energized from a 120V source. Five amps will never trip a 15A or 20A breaker, and in the meantime everything bonded to this ground rod will be energized to 120V.

Last edited by Brian Oshman; 25th July 2010 at 10:11 PM.
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Old 25th July 2010, 10:29 PM   #27
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OK, I see a proven point that some of the terms are somewhat misleading as I stated before. That is why I repeatedly used the terms "safety ground/"earth"/PE" or the green/yellow cable to put it simple. Over here the neutral wire/connection will never be used for safety ground (it is forbidden as well) but I saw it mentioned in some posts which confused me a bit. So PE and Neutral (or "N") are strictly separated although they are connected elsewhere in the installation. It is exactly that strict separation that makes it a consequent system.
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Old 25th July 2010, 10:51 PM   #28
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It is the same here too. The neutral is not the ground. Both are separate connections but the neutral and all grounded parts are bonded together at some point.

This was my point in my original comment to check the integrity of the neutral in the electrical system. The neutral is the mid point in the main transformer and any unbalance will cause noise in an audio system.

You can clamp on all of the capacitors and resistors to the service that you want but that will not get rid of an imbalance. You are just creating another load and therefore another path for electrons to flow. It is not going to eliminate it. The best way is to ensure that the neutral reads zero amps. This is when it is truly balanced as it is canceled out by both phases in reference to it.

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Old 25th July 2010, 10:57 PM   #29
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A nice idea but very difficult in practice with three phase transformers feeding houses with only one phase connected. In my job at a datacentre I tried to balance it out and keep neutral current low by adding newly arrived "load" to different phases with thought and care. Otherwise I would say it is impossible to do in a domestic situation.
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Old 25th July 2010, 11:04 PM   #30
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Quote:
Originally Posted by jean-paul View Post
Very little to no blackouts even with the cabling in the ground.
This is the reason why you don't experience blackouts, the cables are protected from damage. Here in certain parts with overhead service, huricanes, tornadoes, other storms, trees, transportation vehicles, etc... all play a part in uprooting poles and wiring. Underground is much more reliable.
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