On 01/01/2016 05:13 PM, Dave Cole wrote: > Anytime you have a 120 volt source for computer, misc power etc, you > need to declare one side of the 120 vac winding the neutral (white wire) > and tie that terminal to the machine frame. > It similar to what is required at the service entrance of your house. > The neutral is always tied to the ground at the entrance box. > Oftentimes they drive a screw through the neutral buss bar in the > service entrance box into the box sheetmetal and then tie a green or > bare copper ground wire to the same neutral buss bar and run that to a > metal water pipe or ground rod.
You should never tie a secondary winding of a transformer to ground. The transformer makes the secondary float wrt. the primary and that is just fine. In this scenario, you would create a (capacitive) feed-through from the transformer to ground because the primary is not referenced at ground. The primary has two phases attached, which creates a virtual circuit at the primary side. The difficulty here is that you must take account for the floating references, which make most of the things you measure local phenomena. Once you go through the transformer, your reference to the primary line input is lost and you must not try to reestablish it. It would only make things bad and worse. -- Greetings Bertho (disclaimers are disclaimed) ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
