Welcome to the forum, I will just point out that a lot of our members are working a full day, a lot are running their own businesses, but they are more than willing to give up their own free time to assist someone with a well laid out question where the person posting has expressed their level of understanding of an issue and any areas they are struggling with. However very few actually like doing other peoples homework for them when the person asking hasn't even tried to answer the question themselves. This was briefly pointed out in your other thread
http://talk.electricianforum.co.uk/topic/25150-what-sort-of-things-do-you-fins-in-a-substation/. May I suggest you will get a far better response if you asked a question in the format of; "I think that the reason for "A" is because of "B" and "C", but I do not understand "D" can anyone help explain please?" Rather than a "I need to know everything about "A"". It can just come across as a bit selfish and lazy if you don't even try to answer something yourself first, showing your present understanding. The forum is not a homework generator, you can use places such as google & wikipedia for your research. I trust you take this the way it is intended.
Doc H.
