Quote:
Originally Posted by ErichKeane
Er, your computer case IS connected to the negative terminal of the DC power supply, through the brass stand-offs of the motherboard. The power supply itself is the only one routed directly to the 3rd pin AC Common.
And yes, grounding your wood frame would have minimal advantages...
|
In order to pass UL certification and NEC codes, all exposed metal on any line operated device must be tied to building electrical ground. That third pin in the plug connects to an isolated wire that connects to the same point in your power distribution panel that a ground stake, cold water pipe or other wire that leads directly to earth connects. In common 220 volt AC house wiring, the neutral connects to this point as well and
only at this point. However, nuetral current does not flow in the isolated third wire in your home. In those cases where the manufacturer has decided to tie power supply common to the chassis ground connection, the power supply must be isolated from the power line as in a transformer. Line operated power supplies as in TVs (those without transformers) must not be connected to anything that the consumer can touch. Metal connectors on the outside of televisions, are not connected to ground, they are connected to a floating supply common.