
Not according to the NEC nor the CEC, as explained in the electrical wiring 
FAQ, which I posted here separately.  Note the material under the headings


and


Of course, as they said -- "Local codes may vary". 


I'm not sure about this.  If the ground connections on the outlets are
connected to anything, they should be connected to a wire that runs back to the
main panel, where it is bonded to the neutral connector and to the house ground
rod.  A connection to a local earth ground would not necessarily meet one of
the goals of the ground wire, which is that if a short develops from hot
to the ground wire, enough current would flow to trip the breaker.  

Hmmm.  How are those orange "isolated ground" outlets (often used in
computer rooms) wired?  