Electrical question

[scarpi]

Forgive me, I am not too knowlegable about electrical stuff. I want to upgrade the electrical outlets in my duplex 20 amp line for my amplifier. The line has two typical 20 amp outlets wired together (4 plugs). I would like to replace one of the outlets with a better hospital grade outlet. Here is my question. The hospital grade outlet that I bought has what is called an isolated ground. If I wire it in replacing one of my typical 20 amp outlets will there be a problem because the other 20 amp outlet that it will be wired to has what is called a self ground. They share common wiring from the electrical box outside. I hope I described this clearly. Any electricians out there. Or would I be better off just putting in a better typical 20 amp outlet and not the hospital grade one? Thanks, Don ;x(

[Glen B]

You will need to run a wire pigtail from the ground terminal of the IG outlet to the incoming ground conductor in the receptacle box, otherwise any equipment you plug into the outlet will not be grounded. Ideally, there should also be another pigtail from the same incoming ground conductor to the back of the receptacle box.

With regard to receptacles with self-grounding tabs, some electricians will argue that it is best practice to run a wire pigtail from the ground terminal of the receptacle to the metal box, and not rely on the tab alone for grounding.

That is because the self grounding feature works by the tab making contact with the edge of the metal box when the mounting screws are tightened. However, if the mounting screws should come loose over time, the tab will lose contact with the box and grounding will be lost. Running a wire pigtail as described above solves that potential problem.

[Smokinghot]

Electrical codes vary from place to place. However what I can say is that in my area (Ontario, Canada), recepticles must have a wired connection to the incoming ground in the box. It must also share a common connection to ground with the box itself.

FWIW The concept of an "isolation ground" is a joke. For such a system to exist, the ground connection would have to be untapped by any other junction, and unused for any other location, up to the source that generates the ground in the system. That is extremely unrealistic in almost all cases.

I've had my license for over 12yrs.

Hospital grade plugs only place a higher physical pressure on the prongs of your cord end. You may have been able to save yourself some $$$ using industrial grade...which do the same thing. Of course they don't have the pretty green triangle on them though.

[scarpi]

I decided to just use outlets that were heavier duty and make a very good connection rather than use the hospital grade one. Thanks all.