Welcome to the OP,being part of a multi-cultural social circle,i will not be adding any derisive posts,but your questions only sound polite,if i imagine them spoken with a Chinese accent :icon12: Where ever you hail from,the best assistance will gained,from correctly asked questions. Many topics can be discussed without reference to nomenclature,terminology and spelling,but if you are serious,regarding the electrical industry,this is vital...I will give you an example,from my friends late grand father. He was explaining how wording and terminology,could be life or death,and he served as a Sapper,overseas,during and just after WW2. "Knowing the difference between open and closed,could save your life",he said, "Taps and Switches...",he let us ponder for a while,and then explained "The word closed,means your dry with one,and dead with the other..." If you understand this,as you read it,i apologise for my curtness,if not,then press the "Thanks" button...:bobby: