In general, you want the safety ground wired such that it does not have to be disturbed to replace any other components, and protected from loosening, etc. So direct connection to a welded ground stud, with a locking device (washer or nut) is ideal. Other (functional) ground wires can be stacked on the same stud, but must go on TOP of the safety ground locking device.
Any construction which does not provide a single-function, dedicated safety ground should be carefully evaluated and generally requires specific buy-in from test houses/Notified Bodies. If the terminal block you mention is considered a component that could fail and need replacing, then the reliability of the safety ground depends on the workmanship of repairmen, who seldom have or use high-current ground impedance testers. ---------- From: GOEDDERZ, JIM To: 'PSnetPost' Subject: Reliably grounded List-Post: [email protected] Date: Thursday, October 09, 1997 2:27PM I would like to get an industry statement on what constitutes reliable Protective Earth Grounding. I reference IEC950, Par. 2.5, which states that "Accessible conductive parts ...shall be reliably connected to a protective earthing terminal within the equipment." Some safety agencies allow connection of the PE through a terminal block, and others require that the PE connection be made directly, before connecting to any component (including a terminal block). Can I get some response on what has been allowed, or required, in your designs? James Goedderz [email protected]
