Solar array and grounding

Ethan Brush

[quote] FWIW our local installer agrees with you / is a fan of ungrounded systems. But im not convinced. [/quote]

Actually I was referring to equipment grounding not system grounding.  I guess system grounding is another thing that could be discussed.  I know there are some arguments for and against having the system referenced to earth vs floating in regards to lightning.  All in all, I havent read/seen/heard anything that makes me think it matters much either way. 

I am in central NY.  Certainly not the lightning capital of the world, but we get lots of thunderstorms in the summer.

I am just skeptical that adding some more ground rods, bonding jumpers, and other home brew lightning protection will accomplish much beyond the basic NEC requirements and having a few good SPD's. 

BB.

Back in 2013, poster Westom said:

This example demonstrates a few popular myths and how they corrected the resulting 'damage':
http://www.copper.org/applications/electrical/pq/casestudy/nebraska.html

I think this is the study you typed about ZoneBlue.

Here are a couple of nice PDF's that show some practical off-the-shelf hardware for lightning control (note: these links are biased towards HAM radio setups--but the information is still useful):

Selecting and Installing Lightning Protection Devices (1.37M pdf)

Lightning Protection Tech Articles

An informative 3 part article on lighting protection published in ARRL's QST Magazine
Lightning Protection for the Amateur Station
by Ron Block, KB2UYT
Part 1
Lightning protection can be a serious issue for amateurs. In part one, the author leads us through the process of developing a protection plan.

Part 2
In part two the author discusses the characteristics of lightning and the hazard it presents to the amateur, and presents a method of preparing a schematic of a protection plan. This installment also shows us how to design a protective installation and what type of protection is needed.
Part 3
In part three the author shows how to develop a
good external ground system to complete your station’s protection.

Reprinted with permission from QST; Copyright ARRL

Additional Lighting Protection Articles from Polyphaser

An overview of Lightning Protection for Ham Radio Stations
Lightning Protection Tech Articles

And from Westom again:

westom wrote: »

A professional application note demonstrates single point earthing. Two structures. Each must have a single point ground. Any wire entering but structures must connect to that structures single point ground before entering:
http://www.erico.com/public/library/fep/technotes/tncr002.pdf

Earthing requirement applies to every wire in every cable. Even if that cable is underground.

If two structures violate the concept, then a direct lightning strike to one building may become a lightning rod connecting that surge into appliances inside the second building.

Earthing wires to some 3 meter ground rods means a massive increase in surge protection. But better informed builders start protection when footings are poured. Ufer grounds were pioneered in munitions dumps so that direct lightning does not cause explosions. Technology is that routine when surge damage is not acceptable. Effective because concrete is a good electrical conductor.

Buried ground loop is another solution. Or how one solve earthing atop a rocky mountain:
http://scott-inc.com/html/ufer.htm

A case study of how all surge damage was eliminated in a Nebraska radio station by not wasting money on protectors. By fixing defects - bad earthing. They even fixed the utility pole transformer earth ground. Each layer of protection is only defined by that earthing electrode - each single point ground; not by any protector:
http://www.copper.org/applications/electrical/pq/casestudy/nebraska.html

Welcome to what advertising and salesmen in a big box TV / computer store will not discuss to enrich themselves at your expense.

-Bill

Ethan Brush

Thanks for the links Bill.  I find that  a careful study of the Nebraska case study, reinforces my point.  You have a number of real basic things that were not done right: grounding electrode conductors and bonding jumpers disconnected/corroded, connections made with hose clamps, current flowing on the equipment grounding conductors due to a N-G bond, etc.  Then you have these jokers from CPC (I have heard of them before) come in, fix that stuff and add a good quality TVSS - thats all great and likely all that was needed, but then they do all this ridiculous stuff with "deep earth grounding", install 250 kcmil grounding electrode conductors, 50 foot ground rods, etc.  I read a similar story a few years ago  and it went similar: fix the basic stuff, but then do the "deep earth" con......

Sorry to sound so opinionated and pessimistic.  I just get frustrated by this idea of a "good ground" or "better ground".   It is a very prevalent idea that a low ground resistance is important/better but has little scientific basis or statistics to support it, except for some specialized applications and situations ,as far as I know.   Over at the Mike Holt code forum (a 'people in the trade only' forum) there are a lot of real knowledgeable guys over there, some are on the code making panels and  quite a few EE's as well, and pretty much all of them would take a similar stance on this.