Foolish of you to make that claim when you clearly don't understand a word they say.
Connecting oven + induction hob
- Thread starter maciej
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Excuse my ignorance, and I am very ignorant about such matters, but does that quote not prove winston right? Based on that last paragraph?
No, it doesn't.
Our supply voltage has always spanned a range of a nominal value ± a certain percentage.
It still does, but the nominal value and ±% have changed. Winston does not understand this.
When that book being quoted was written, the nominal voltage to be used in calculations was 240V. It is now 230V. The Wiring Regulations are quite clear on this. But Winston does not understand them.
Our supply voltage has always spanned a range of a nominal value ± a certain percentage.
It still does, but the nominal value and ±% have changed. Winston does not understand this.
When that book being quoted was written, the nominal voltage to be used in calculations was 240V. It is now 230V. The Wiring Regulations are quite clear on this. But Winston does not understand them.
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www.tlc-direct.co.uk may not have changed what is written in their book but others have.
A B type MCB is designed to trip within 0.01 seconds when the current exceeds 5 times the rated current using the magnetic part of the trip.
For this to happen a short circuit must allow that amount of current to flow so the IET/BSi in their book BS7671 have published the loop impedance figures required to ensure with a short circuit enough current will flow to cause the device to trip using the magnetic part.
Taking an example a B32 in BS7671:2001 is listed as requiring 1.50 ohms table 41B2 but in the BS7671:2008 edition this is now 1.44 ohms table 41.3 this reflects the change in voltage.
However the voltage is not the issue here. It's the supply type. I realise there is no reason why a house in UK should not have a 230 - 0 - 230 volt supply however this seems to be only found in things like farms and caravan sites and even with the farm the house will normally have a 0 - 230 volt supply. However in the rest of Europe it is far more common to have a 230 - 0 - 230 volt supply as the population is not as dense. The step down transformer is much smaller when supplying 460 volt than when supplying 230 volt for the same amount of power.
As a result large current using appliances will spread the load over the two phases and many hobs have links to allow it to be used either with split phase or single phase.
Consumer units and MCB's will clearly need to allow for this system and so will the wiring of the house. As to exactly how this is done I don't know. I did work on the earlier 110 volt system often three phase where only 190 volt between phases so unlike the USA system you can't use two phases to run 220 volt equipment.
I just can't see how we in the UK can jump in with both feet and advise some one in France who could have things we have never seen. There is an "Electrics Outside of the UK" section and this is where this post should have been.
Yes in a town in France likely same system as us. Although twin pole MCB's are found even in towns and although the French sockets are non reversible like ours often they use German sockets or have plugs which will fit in either. As to what they use for 32A supplies I have no idea. When I worked for a French firm we had metal plugs and sockets and you had to turn the plug in the socket to operate the built in switch and press a button to release plug and switch off. One could hardly have a splitter on this system.
It is interesting seeing what other countries do but to advise on a system where we have very little knowledge of how it is done and also of course what laws are in force is likely to cause problems for the guy posting.
In this country our Part P laws differ as we go from one principality to another this could also be true in France so I would say unless you have a working knowledge of the French system to advise in any depth is wrong for this post.
A B type MCB is designed to trip within 0.01 seconds when the current exceeds 5 times the rated current using the magnetic part of the trip.
For this to happen a short circuit must allow that amount of current to flow so the IET/BSi in their book BS7671 have published the loop impedance figures required to ensure with a short circuit enough current will flow to cause the device to trip using the magnetic part.
Taking an example a B32 in BS7671:2001 is listed as requiring 1.50 ohms table 41B2 but in the BS7671:2008 edition this is now 1.44 ohms table 41.3 this reflects the change in voltage.
However the voltage is not the issue here. It's the supply type. I realise there is no reason why a house in UK should not have a 230 - 0 - 230 volt supply however this seems to be only found in things like farms and caravan sites and even with the farm the house will normally have a 0 - 230 volt supply. However in the rest of Europe it is far more common to have a 230 - 0 - 230 volt supply as the population is not as dense. The step down transformer is much smaller when supplying 460 volt than when supplying 230 volt for the same amount of power.
As a result large current using appliances will spread the load over the two phases and many hobs have links to allow it to be used either with split phase or single phase.
Consumer units and MCB's will clearly need to allow for this system and so will the wiring of the house. As to exactly how this is done I don't know. I did work on the earlier 110 volt system often three phase where only 190 volt between phases so unlike the USA system you can't use two phases to run 220 volt equipment.
I just can't see how we in the UK can jump in with both feet and advise some one in France who could have things we have never seen. There is an "Electrics Outside of the UK" section and this is where this post should have been.
Yes in a town in France likely same system as us. Although twin pole MCB's are found even in towns and although the French sockets are non reversible like ours often they use German sockets or have plugs which will fit in either. As to what they use for 32A supplies I have no idea. When I worked for a French firm we had metal plugs and sockets and you had to turn the plug in the socket to operate the built in switch and press a button to release plug and switch off. One could hardly have a splitter on this system.
It is interesting seeing what other countries do but to advise on a system where we have very little knowledge of how it is done and also of course what laws are in force is likely to cause problems for the guy posting.
In this country our Part P laws differ as we go from one principality to another this could also be true in France so I would say unless you have a working knowledge of the French system to advise in any depth is wrong for this post.
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Its in there with no replies !
That's interesting - but, from all I've heard, you are in a (probably fairly small) minority. The impression I get is that most UK supplies (like mine) are appreciably higher than that, close to or above 240V. Mine is usually 242V-246V, and I can't recall ever having seen it below 240V.
I thought that only happened (or was meant to happen) with genuinely 'high' supply voltages - certainly above 250V. Am I wrong? I find it hard to believe that a DNO would reduce a supply voltage which is within the permitted range (i.e. 253V or lower) because of a customer's mal-designed or mal-adjusted solar installation.
Kind Regards, John
Yes the whole idea that the DNO would adjust the voltage to comply with europe or for Solar installations is ridiculous.
Much more likely to change a few tollerances, so it complies on paper.
Much more likely to change a few tollerances, so it complies on paper.
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