[TowerTalk] Grounding Multiple Buildings

[Jim Lux]

On 9/14/14, 2:56 AM, Jim Thomson wrote:
> Date: Sat, 13 Sep 2014 18:26:13 -0700
> From: Bill Turner <dezrat at outlook.com>
> To: Towertalk <towertalk at contesting.com>
> Subject: Re: [TowerTalk] Grounding Multiple Buildings
> Message-ID: <BLU436-SMTP128B560C5A6AFC544667360C0CB0 at phx.gbl>
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>
> ------------ ORIGINAL MESSAGE ------------(may be snipped)
>
> On Sat, 13 Sep 2014 16:22:23 -0700, k9yc wrote:
>
>> This afternoon, I pulled out my 2002 copy of NEC and found the section
>> applicable to what we have been discussing. I suggest that those who
>> rail at my stupidity and tell me how wrong I am do the same.
>
> REPLY:
>
> Anyone who digs up an obsolete copy of something to prove that he has
> the "right" to create a safety hazard has a larger problem than we can
> help with here.
>
> 73, Bill W6WRT
>
> ##  Agreed.  It baffles me why the code allowed for NO grnd conductor between building ..
> back in 2010..that is fubar.  Why the 4 wire code in 2011, when everyone else had it eons b4.
>
> ##  here we cant even buy electrical cable that does not include a ground wire.
> Its been like that at least as far back as 1960, here in VE7 land.
>

Mmm. what about the rules for 220V dryer plugs. if you want something 
that's just crazy

grounding and bonding is a VERY contentious issue in the electrical code 
making.  Somewhere on the web (don't recall the URL) there are the 
minutes from the committee meetings.

There was a huge issue after the MGM Grand fire, because it, in part, 
was due to how grounding/bonding was done (and what turned out to be 
really bad architectural design of a suspended ceiling that facilitated 
the spread of the fire).

And there's been a number of cases with swimming pools and grounding issues.

The rapid growth in the use of switching power supplies which draw 
non-sinusoidal currents has also been a factor in the whole "what do we 
do with the neutral" issue.



Recently, they're trying to get rid of the whole "grounded conductor" 
(white wire) / "grounding conductor" (green wire) terminology, because 
it's confusing.  Safety Ground, "bonding conductor", etc.



But there are a LOT of things out there that use those terms, and will 
continue to do so.  Heck, there's a lot of places that still have 2 
prong receptacles.  Why do you think they have GFCIs integrated into 
bathroom appliance cords now?


Not only that, but in most places the *current* NEC does not have the 
force of law or regulation.  What you have is a weird combination of 
state, county, and local laws.  A typical jurisdiction will adopt some 
version of the NEC as their local electrical code, make some locally 
advised changes, and that's what will be "the rule" in that area until 
someone changes.  If NFPA goes out and issues a completely revised code, 
for very good reasons, all those cities, and you personally, might be 
subject to the old code, even for new construction.

That's why when you read questions or fine print notes or commentary, 
there's always references to the "Authority Having Jurisdiction" (AHJ).
This is not unique to municipal regulatory matters: I was installing a 
Fisher-Paykel dishwasher that came with pages of instructions on how to 
do installs in a kosher kitchen, each page with a disclaimer on it about 
how this might not be how you need to do it.  An orthodox friend 
explained it.. there's a phrase in Hebrew that I can't recall, but it 
boils down to "Consult your local rabbi for clarification and local 
interpretation of the rules"

What really counts, from a regulatory standpoint, is whether the 
inspector will sign off on it.  I'm sure many of us have had an 
inspector ask us to do something that may not make total sense, from a 
code standpoint, or an engineering standpoint.  But the inspector is 
"the Authority".. If he/she wants green tape wrapped around the wire in 
a clockwise direction, then I'm going to wrap green tape in a clockwise 
direction.  By and large, though, most of those weird inspector/local 
procedure aspects DO address some local peculiarity in how things are 
done, or mitigate the possibility of the recurrence some spectacular 
egregious event that occurred 20 years ago.