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Swimmer
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Discussion Starter · #1 ·
A supplier of industrial ground fault equipment sent me a booklet on grounding.
The first thing I saw, Figure 1, was ground rods driven at both the transformer secondary and the breaker panel down stream. These ground rods are connected by a grounding electrode conductor (GEC). The transformer enclosure seems to be bonded via a circuitous route through the GEC to the breaker panel enclosure and then back through the "Bonding jumper" to the transformer enclosure.


The top drawing is from the booklet.
The bottom drawing is how I think it should be.

This company deals with industrial customers and I do mostly residential but I've been on a few industrial jobs with transformer / panel setups and I've never seen the setup shown at top.
 

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A supplier of industrial ground fault equipment sent me a booklet on grounding.
The first thing I saw, Figure 1, was ground rods driven at both the transformer secondary and the breaker panel down stream. These ground rods are connected by a grounding electrode conductor (GEC). The transformer enclosure seems to be bonded via a circuitous route through the GEC to the breaker panel enclosure and then back through the "Bonding jumper" to the transformer enclosure.


The top drawing is from the booklet.
The bottom drawing is how I think it should be.

This company deals with industrial customers and I do mostly residential but I've been on a few industrial jobs with transformer / panel setups and I've never seen the setup shown at top.
The way you have it is correct.

There's a mike Holt video that discusses this, I'll see if I can find it and post it later on,stay tuned.:)
 

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Swimmer
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Discussion Starter · #3 ·
The way you have it is correct.

There's a mike Holt video that discusses this, I'll see if I can find it and post it later on,stay tuned.:)

Thanks Harry. No need to post unless for the benefit of others viewing this thread. I've been going through those Mike Holt grounding videos. He's right about all the confusion in the industry.
 

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Swimmer
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Discussion Starter · #4 ·
When to install ground rods?

It looks to me like you install ground rods:

1. At utility transformer poll connected to utility transformer secondary.

2. At service between meter and main. Actually, this is where the electrode grounding conductor would be attached but you get what I mean.

3. Between secondary of separately derived system transformer and breaker panel down stream.

4. At the ground bus of a sub-panel in an secondary building. The service, in this case enters the primary building and feeders supply the sub-panel in the secondary building. Typical unattached garage, multiple circuit set-up.

Is it a violation to install ground rods at panels within the same building as shown in the equipment manufacturer's drawing at the start of this thread?
 

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Are we to assume this a MDP fed via rigid from the Xformer swimmer?

~CS~
 

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I admit, I don't know.

The diagram looks like that if there were a fault to ground at the XFMR, the fault path would be Bonding Jumper--->Equipment Ground--->System Ground---->Neutral. That doesn't make much sense to me.
 

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At least most companies out this way are getting (or have gotten away) from installing hundreds of ground rods across a site.. Usually now only around electrical rooms, radio towers and buildings that are on a concrete pad.. Most have given up on a ground rod next to a pile for a building and burying a 2/0 loop of insulated ground wire around the outside perimeter of the building...
 

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Discussion Starter · #10 ·
Are we to assume this a MDP fed via rigid from the Xformer swimmer?

~CS~

Steve, I was looking at the picture as, for example, a 480 / 208 transformer downstream of the main distribution panel. I've worked on this part of the system but never upstream of such a transformer so my knowledge of MDP is limited. I assume an MDP contains a 600A main, or something on that order, and is fed by the power company. I also assume an MDP would have a meter.

If the panel shown in the picture is an MDP then the delta-wye transformer would belong to the power company, and both the transformer and the MDP would have ground rods as shown in the top picture. Also, if this was an MDP, I'd expect to see a meter. I would not expect to see the connection labeled "System Grounding" which looks to me like a grounding electrode conductor.
 

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Well ok Swimdude,

First off the meter on most anything over 400A is CT, so don't even worry about it

Secondly, consider the poco xformer it's own entity, complete with it's own grounding requirements, not exactly the normal 480/208 deal you may be used to

Third, consider your main MDP where the premis grounding all terminates to a MBJ (main Bonding Jumper) Perhaps this is where the confusion exists, in part because of the semantical nature of art 100, now inclusive of 'Main' and 'System' bonding jumper both descriptive of an N & G bonding in different situations

Lastly, consider the return path noodle for the entire install. This is the stumper that gets even masters rattled btw, because the theory and practical application often clash

hope that helps ~CS~
 

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Lastly, consider the return path noodle for the entire install. This is the stumper that gets even masters rattled btw, because the theory and practical application often clash

hope that helps ~CS~
Sorry for the newb question but could you explain this. Maybe I'm trying to learn to much too soon, if that's possible.
 

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Well ok Swimdude,


Lastly, consider the return path noodle for the entire install. This is the stumper that gets even masters rattled btw, because the theory and practical application often clash

hope that helps ~CS~
The correct term is NEUTRAL, jack legs and hacks may call it a noodle but professionals call it a neutral, a ground conductor but NOODLE HELL NO.

I hate that term and while we are at it Tranny can go away as well, we are suppose to be professionals can we use professional terms?
 

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The correct term is NEUTRAL, jack legs and hacks may call it a noodle but professionals call it a neutral, a ground conductor but NOODLE HELL NO.

I hate that term and while we are at it Tranny can go away as well, we are suppose to be professionals can we use professional terms?
Ok:thumbsup:....then i challenge you to define neutral

but here's the kicker Brian....not just in it's domestic usage

in it's international meaning juxtaposed to application

~CS~
 

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Ok:thumbsup:....then i challenge you to define neutral

but here's the kicker Brian....not just in it's domestic usage

in it's international meaning juxtaposed to application

~CS~
In the trade which we choose to work a neutral is a common term as defined in the IEEE 100 The Authoritative Dictionary of IEEE Standard Terms 7th Addition.

A noodle can be a food product, a noodle head as in a dumb ass or you might call your d*ck a noodle but to converse with other professionals across the expanse of Canada, America and the slew of other countries that visit this site we are better served with proper terminology as in the word neutral.
 

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'Neutral' , WAS trade slang for over a century in the NEC Brian

GroundED and GroundING conductors were considered proper terminology until recent times

The rationale the CMP forwarded was simply because enough of the trade used the slang term to enable it's officiation

So in fact, if my noodle* term had taken off from it's inception some 20 yrs ago, it might have rated CMP advocation :thumbsup:

That said, reducing any debate's underlying concept or theory to droll non sequitur semantical banter is so last Tuesday here

Again. i challenge you (et all) to rise above it





*all rights reserved by the chickenman, chickenman's hiers and the estate of chickenman

~CS~
 

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'Neutral' , WAS trade slang for over a century in the NEC Brian

GroundED and GroundING conductors were considered proper terminology until recent times

The rationale the CMP forwarded was simply because enough of the trade used the slang term to enable it's officiation

So in fact, if my noodle* term had taken off from it's inception some 20 yrs ago, it might have rated CMP advocation :thumbsup:

That said, reducing any debate's underlying concept or theory to droll non sequitur semantical banter is so last Tuesday here
No debate here, take a license test for our trade and use the word noodle, you will be laughed out of the class room.

Steve It is in the IEEE Dictionary, find noodle anywhere in the IEEE Dictionary otherwise, case closed.

Many words that were slang become the accepted word and show up in approved dictionaries and NOODLE ain't one off them in our trade.
 

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How many groundING vs groundED conductors are there in the top photo?


~CS~
 

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A supplier of industrial ground fault equipment sent me a booklet on grounding.
The first thing I saw, Figure 1, was ground rods driven at both the transformer secondary and the breaker panel down stream. These ground rods are connected by a grounding electrode conductor (GEC). The transformer enclosure seems to be bonded via a circuitous route through the GEC to the breaker panel enclosure and then back through the "Bonding jumper" to the transformer enclosure.


The top drawing is from the booklet.
The bottom drawing is how I think it should be.

This company deals with industrial customers and I do mostly residential but I've been on a few industrial jobs with transformer / panel setups and I've never seen the setup shown at top.

Not ground rods necessarily. What the supplier/designer is indicating with this typical schematic is that the equipment grounding conductors and system grounding have the same potential.
 
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