Multi-Point Grounding System

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cuba_pete said:
...it's roughly 70% getting it to start, then 30% implementation (in my experiences). This is also why we try to keep the same contractors doing work for us "sole source".....
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So you have got a group of guys who have worked out all the kinks; figured out what you mean instead of what you say and have not offended you in the process. Fair enough.
 
captainwireman said:
There must be a way to contact the manufacturer of the skid/building. I would think they would have more relevant information as opposed to the customer.
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I am the manufacture of the pre-cast shelter ;) They are poured, assembled and integrated on site, we do everything in house, concrete, wall finish, electrical, flooring, doors etc... This is just the first one I have dealt with the FAA specs in this case. Our standard grounding we have adopted from Motorola's R-56 specs.
 
So, to end all confusion or start more for that matter...Here is the end result in the "multi-point" grounding system in a 192sqft precast shelter.

Finally got what the FAA wanted for grounding in there shelter:

(1) #4 from the MGB to the MTS, MDP, TVSS #1, Panel 'B', and TVSS #2 ( in that order) all being connected with a 2hole single barrel mechanical lug externally attached to the top of each.

(2) A #6 from each of the anti-static floor grounding ribbons, total of (4), ran back to the MGB for a total of (4) individual runs.

(3) A #6 from the cable tray to the MGB and a #6 jumper from the cable tray to the the wire-way on the ceiling.

I will post pics when we are done with this. :thumbsup:
 
don_resqcapt19 said:
I would expect in many cases, that is a direct reflection on the quality of the construction documents and not on the quality of the worker.
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That's a pretty brave assumption, but :happysad: nope...

In the last five years I have encountered no less than three Master Electricians who did not understand that the use of isolated ground receptacles did not preclude the proper grounding and bonding of the electrical system. They wanted to use truly isolated ground rods....as in not bonded. One master didn't even run a ground to the panel before he applied his sticker.

These were Master Electricians from North Carolina, Washington (owned his own business), and California.

The drawings were very clear on the proper use of single-point grounds...and in accordance with the NEC.
 
ActionDave said:
So you have got a group of guys who have worked out all the kinks; figured out what you mean instead of what you say and have not offended you in the process. Fair enough.
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bwah ha ha!:lol:

Not quite. Normally I have to explain to the design engineer why his ideas won't work in my facility, then walk the electricians (of all "qualifications") through the proper methods. The design engineers just about blow a gasket and the electricians just shake their heads.

One Master wanted to know why when he connected a cabinet to the single point ground (which he incorrectly called an isolated ground) he got less than 1-ohm to building steel. I said something like, because it's bonded? And he continues...I thought it was an isolated ground? :weeping:

It's not being shitty or anything...it's just what needs to be done to make sure the job is done correctly. If they would just follow the drawings and apply the IEEE/NEC we'd all be happy.

True, most electricians don't do much work in technical environments which have specific or exacting standards. We used to have dedicated teams from AT&T who did all of the work. When AT&T was determined to be too big, smaller contractors showed up and hired local contractors for one-off installations. Most of the time the contractors had only done small commercial or residential work.

Government/MILSPEC/technical communication work befuddles a lot of electricians even though the NEC still applies (and a lot of states test on it)...and I'm like...just follow the code!

</soapbox>
 
cuba_pete said:
That's a pretty brave assumption, but :happysad: nope...

In the last five years I have encountered no less than three Master Electricians who did not understand that the use of isolated ground receptacles did not preclude the proper grounding and bonding of the electrical system. They wanted to use truly isolated ground rods....as in not bonded. One master didn't even run a ground to the panel before he applied his sticker.

These were Master Electricians from North Carolina, Washington (owned his own business), and California.

The drawings were very clear on the proper use of single-point grounds...and in accordance with the NEC.
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Well then you get much better drawings and specs than we do:) I haven't seen what I would call a quality set of drawings in about 20 years.
 
Installation requirements do vary from customer to customer

Installation requirements do vary from customer to customer

don_resqcapt19 said:
Well then you get much better drawings and specs than we do:) I haven't seen what I would call a quality set of drawings in about 20 years.
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Don I think that you have said it all. I have had AHJs as diverse as the Corps of Engineers and the owner of a totally unregulated embassy's building manager. I have done Electrical Equipment Shelter installs from Tierra del Fuego to Alaska and Myanmar to Uganda and the difference in the quality of the installation documentation is boggling. Even when I was only functioning as the manufacturers liaison on the install I had to spend a lot of time getting the various actors to follow the same stage directions. How was I to know that neutral conductors in South America were generally blue in color. One week I'm on the factory floor bending a hundred repetitions of each piece of conduit for an order of shelters and the next week I was in Buenos Aires trying to explain why I wanted four conductors in the single phase feeder to our shelter which is to be assembled under an existing radio tower in an existing telephone company complex but that I don't need four conductors to the utility transformer on a brand new site. The only ones that were easy to get installed were the totally self sufficient units that were assembled on remote ridge lines with their own hybrid power production as part of the install. It took me a long time to understand that the reason that Telefonica Argentina wanted Steel used in the construction of shelters that had to be sited using Helicopter hours was that the steel walls had a better chance of withstanding the plinking from the 30/30 carbines of the bored Gauchos on the pampas below. It probably didn't help that the only Spanish phrase that I new was "donde esta el ba?o"

A colleague of mine at that same company had to install a photo voltaic array on a site were the biggest shadow effect on the array was the government power lines that the missionaries were unwilling to pay the "fees" needed to get connected to them. Idi Amin Dada's customs officials stole his clothes on the way into the country so that he had to spend two weeks in the same set of clothes by washing out his underwear by hand each evening.

It is a much different world for the traveling electricians that install under such diverse conditions than it is for someone who has only one site and one set of rules to deal with.
 
no kidding...

no kidding...

I didn't even try to enforce any type of code with the Jamaicans, Haitians, or Cubans...if they had one.

Overseas contractors used to do some really goofy stuff.
 
The framework can be ascertained as a spatial capacitor and ought to additionally be intended for the frequency of hobby.
 
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