Is it permissible to high impedance ground the circuits not to be grounded,identified in 250.22,as long as it is done in accordance with 250.36?
And if not, why not?
Heinz R.

As a separate issue, why does this web page now show up in Portuguese rather than English?

Heh heh Heh.
I added that language for one user.
But you should not see it unless you opted for it.
Try going to mystuff>Edit preferences.
The first item is language.
Or you can scroll to the bottom of this page and do the same.

Never mind I changed it for you.

NO!

High Impedance GROUNDED systems are GROUNDED systems. The Systems identified in Section 250.22 are not permitted to be grounded, period.

Brian:
That was my feeling, as well, but I don't understand why. The reason some systems are not permitted to be grounded is to prevent OCPD operation, possibly generating a spark in hazardous atmospheres, when a single round fault occurs. But in a high-Z grounded neutral situation the OCPD would also not operate on the first ground fault. And, if the High-Z neutral ground complies with 250.36 it strikes me as being as safe in that respect as the "no-ground" requirement of 250.22. Furthermore, although there is no physical, conductive, connection to ground in an ungrounded system, there is capacitive coupling to ground through the transformer winding insulation. How is this capacitive coupling very different from a high-Z ground?
I'm just thinking around in circles and am looking for an explanation why "no-ground" is safer than "high-Z" ground.
Heinz R.

Ruben:
Just for your information I had NOT opted for the Portuguese language. In fact, I didn't know that this could even be done.
Heinz R.

Cool, maybe I can understand this better in portugese.

HA!!! I was thinking the same thing Paul!!!

I think I will watch "Back-to-the-Future" tonight to get a refresher on capacitive coupling and high-z grounding. That's how Deloreans time travel, right?

In all seriousness, I would guess the difference is that capacitive coupling is a natural, unintentional electrical phenomenon, whereas high impedance grounding is an initentional electrical connection to ground a system.

Where is Dick Widera when you need him???

Bryan:
Seems I'm wrong again. I always thought Deloreans time travelled in very expensive sports cars with gull wing doors, sort of like the DMC-12.
In seriousness, I understand that one grounding is incidental while the other is intentional but is there any significant arcing difference between the two on first ground fault at the ground fault location? It's the only thing that comes to mind why high impedance grounding would not be allowed in the hazardous circumstances listed in 250.22 and I'm guessing that the absence of ground also reduces the shock hazard on first ground fault in underwater low voltage lighting, but all that is pure conjecture on my part.
Heinz R.