Physis,
I'm aware that GFI protection is not required in this case (well, there is the issue of the cooktop not being listed for outdoor use); and yes, grounding the non-current carrying parts of a tool or appliance is exactly what I think an EGC is for.
By grounding I mean keeping the non-current carrying metal parts of the equipment at zero (earth) potential, so that there is virtually no chance of shock or electrocution. This is accomplished by providing, via the EGC, a path back to the source for anything from leakage current to a dead short.
And yes, I know that the current will divide among any and all paths available. With a solid EGC, though, there's virtually no chance of getting hazardous current through a person.
It appears that you think the only way to accomplish personnel protection against shock or electrocution from stray current is with a GFCI. I disagree; the EGC was used for that purpose for decades before GFCI technology became available.
I am aware that the GFCI offers advantages over a grounding receptacle outlet. For instance, in a branch circuit with multiple and poorly made EGC splices, the impedance of the equipment grounding path may be high. High enough, in some cases, that a person begins to represent a sufficiently low-impedance parallel path that dangerous current may pass through the person.
Also, in a cord-and-plug connected appliance or tool, the EGC may easily be (and often is) defeated by improper use of an adapter, or by cutting off the plug's grounding pin. Sometimes, the cord is damaged, compromising the EGC in the cord. That's why GFCIs are required to protect cord-and-plug connected equipment in locations where a person is likely to present a good return path for stray energy.
Conversely, that's why there are few requirements that hard-wired equipment be GFCI-protected. There's no cord or plug to be damaged or tampered with; there's no cordset to be damaged; and, with the typical dedicated circuit for a fixed appliance, the EGC usually has fewer splices (and there's a lot less opportunity for EGC splices to be tampered with).
The other reason for not requiring hard-wired equipment to be GFCI-protected (except for spas, hot tubs, etc) is leakage current. For instance, fixed electric outdoor deicing and snow melting equipment is required to have GFPE (ground fault for protection of equipment, tripping at more than 6 mA and less than 50mA) protection, because a GFCI is likely to trip from leakage current.
Leakage current is not an inherent danger; it's when there's no good equipment grounding pathway that it's a problem, and that's what GFCIs are for. GFCIs are a great safety device, but they're not a panacea.
Cliff
[This message has been edited by amp-man (edited 01-05-2005).]
[This message has been edited by amp-man (edited 01-05-2005).]
