13-10-2012, 11:32 AM
Hi Mark,
Re: your post #37: thanks. I read all of that and, yes, it is in agreement with my understanding of 3-phase electrical power distribution networks. So presumably, the IT network is used solely for such distribution networks: e.g. a sub-station transformer with delta-connected primaries and star-connected secondaries. In which case, the Wiki. drawing is confusing, since it shows the 3-wire delta feed to a box labelled 'consumer'. In an electrical power distribution network, to me, a 'consumer' is the 'end user': factory or domestic, not an network distribution transformer. I suppose that one could argue that the use of the word 'consumer' here includes a customer-owned delta-star transformer situated on the consumer's premises - such as a factory requiring 230-v. and 415-v. feeds. In which case, I am of the opinion that the Wiki. drawing should make that clear, at least in text, ideally in a supplementary drawing.
As I mentioned in an earlier post, I studied 3-phase electrical systems in depth many years ago at college, but no reference to earthing systems featured in those studies. Consequently, modern earthing systems are of interest to me and I am learning a lot of useful stuff here via this thread. Your contributions - and those of others here - are of value to me.
Cheers,
Al.
Re: your post #37: thanks. I read all of that and, yes, it is in agreement with my understanding of 3-phase electrical power distribution networks. So presumably, the IT network is used solely for such distribution networks: e.g. a sub-station transformer with delta-connected primaries and star-connected secondaries. In which case, the Wiki. drawing is confusing, since it shows the 3-wire delta feed to a box labelled 'consumer'. In an electrical power distribution network, to me, a 'consumer' is the 'end user': factory or domestic, not an network distribution transformer. I suppose that one could argue that the use of the word 'consumer' here includes a customer-owned delta-star transformer situated on the consumer's premises - such as a factory requiring 230-v. and 415-v. feeds. In which case, I am of the opinion that the Wiki. drawing should make that clear, at least in text, ideally in a supplementary drawing.
As I mentioned in an earlier post, I studied 3-phase electrical systems in depth many years ago at college, but no reference to earthing systems featured in those studies. Consequently, modern earthing systems are of interest to me and I am learning a lot of useful stuff here via this thread. Your contributions - and those of others here - are of value to me.
Cheers,
Al.
