Earth referencing and safety?

F

fastline

Senior Member
Location
midwest usa
Occupation
Engineer
I keep having conversations with people on this stuff and curious if other parts of the world use better terminology to describe all of this? I probably stand as a sole minority, but it annoys me what all the word "ground" refers to. If you pull the grounding electrode out, or disconnect, you can't even call it a ground really, it's a safety circuit and nothing more.

All I know is I have to remind people about what this "catch all" term is supposed to imply, then keep your ECG and EGC straight! So you don't feel dumb!

I guess maybe somewhat of a rant, but I feel the NEC should make changes to help people understand it. It's like the USA that won't adopt the metric system....lol
 
ECG and EGC? Not sure what you're asking but your correct that the terminology is important in helping people understand what it is we're talking about.
 
Our moderator, don_resqcapt19 (as well as others) have made numerous proposals/inputs on this subject. IMO "earthing" should be used for grounding, "bonding" should be used for the EGC/EBC
 
roger said:
IMO "earthing" should be used for grounding, "bonding" should be used for the EGC/EBC
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Yes changing EGC to EBC is a no brainer because EGC is not the proper term when we're actually referring to bonding. I would guess that the number of PI's to make the change is in the hundreds but I wouldn't expect the CMP to accept it any time soon. I'll live with EGC as long as you don't call it a ground. :)
 
I guess I am recalling when I did some back shop teaching and trying to reinforce the critical words "Earth and reference". It's critical to understand something can seem "grounded", but if not referenced to Earth, it is considered floating, as in 'only sometimes bad'. Where things get sideways is this "why bond once? What happens if more than one?" All you have to do is follow the current to realize you create a two conductor, parallel path, which is not cool.

What I don't like about EGC/GEC is they are WAY too similar of acronyms IMO, but very different in what they try to imply. I'd go so far as to wildly separate to help understand the differences. Say ERE=Earth reference electrode, SGC = safety ground conductor. yeah, I just spit that out. But this is also how I remember them.

More or less just wondering if others give this any thought? I mean, there is a whole section on this site, dedicated to just this, in which, IMO, could mean it's hard to understand, though the concepts are simple, and I believe it's because you are doing TWO things with that conductor system, and that should be more clear!

As an example. Consider an HVAC schematic. Normal to see a bunch of black lines, but someone got smart and used dashed line or evel color coding to define the high from low voltages. It is WAY easier to look at!
 
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fastline said:
I keep having conversations with people on this stuff and curious if other parts of the world use better terminology to describe all of this? I probably stand as a sole minority, but it annoys me what all the word "ground" refers to. If you pull the grounding electrode out, or disconnect, you can't even call it a ground really, it's a safety circuit and nothing more.

All I know is I have to remind people about what this "catch all" term is supposed to imply, then keep your ECG and EGC straight! So you don't feel dumb!

I guess maybe somewhat of a rant, but I feel the NEC should make changes to help people understand it. It's like the USA that won't adopt the metric system....lol
Click to expand...
There is no place in the code where the term "ground" is used without other descriptive words, other than when talking about the connection to earth.
The use of the term ground by itself happens all the time in the field.

When that term appears by itself in a question on this forum, my typical comment to the poster is that I have no idea of what is being asked. Additional words are always needed to determine what is being asked about.

I disagree that the connection to earth is really a safety circuit for systems 1000 volts and less.
 
I'm normally would agree, the terms are whack and should be changed. I will play "devils advocate" here though and offer another perspective.

When I started college I was a botany major and Chem 109 was one of the required classes that people usually took in the first year. The class was designed to be a "weeder" class, the instructor told the class on the first day that at least 60% of the class would fail out. If you were serious about getting a science degree, you had to get through that filter, many people took it at least twice. For other reasons entirely I switched degrees, but that's another story.

My point here is that I've grown to appreciate the potential for confusion because it clearly separates those who take the time and effort to understand versus those who can't or won't. As an inspector it allows me to quickly gauge someone's level of understanding of the subject. If they don't understand the difference, I know I have to be a little bit more attentive.

Again, I'm not saying I wouldn't like to see this changed, just saying that over time it's grown on me and I'm less concerned about it.
 
don_resqcapt19 said:
There is no place in the code where the term "ground" is used without other descriptive words, other than when talking about the connection to earth.
The use of the term ground by itself happens all the time in the field.

When that term appears by itself in a question on this forum, my typical comment to the poster is that I have no idea of what is being asked. Additional words are always needed to determine what is being asked about.

I disagree that the connection to earth is really a safety circuit for systems 1000 volts and less.
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I do agree on the word "ground" sort of being loose in industry.

If I conveyed that earth is a safety circuit, that was not my intent. The 'safety' aspect is driving fault currents back to the grounded conductor to blow the OCPD. I was I guess trying to say there are two systems here, doing two different things, and two different purposes.

Where I think things get sideways is DIYers, they have the NEC book, but know very little, and honestly should NOT be touching. But they do. I think it needs to be more clear.
 
ActionDave said:
In Europe they call it Protective Earth instead of Equipment Ground. I could live with that.
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I mean.....I could almost say that is worse! At least IMO. this nearly implies that Earth and equipment ground are the same. I think in the field, I've run into people proclaiming you don't need a grounding conductor at all because you can just drive a GE and you're done!

Then have to get into the word "bond", in which I've learned NEVER to use that word in the field, even though bonding has 1000s of implications. I can 'bond' two pieces of plastic together. I have to be super careful when I say to bond something. Have to say 'connect'.

Guess how many times I've been in a machine to see both the neutral and ground conductors connects to the "N"? If it fits, it ships! They get in, see the N, put neutral there. then have a greenie with no place to live. Just land it here. machine runs. Who cares! Oh your sensitive electronics are not happy? that doesn't even cover the potential differences between N and G.
 
Joe.B said:
I'm normally would agree, the terms are whack and should be changed. I will play "devils advocate" here though and offer another perspective.

When I started college I was a botany major and Chem 109 was one of the required classes that people usually took in the first year. The class was designed to be a "weeder" class, the instructor told the class on the first day that at least 60% of the class would fail out. If you were serious about getting a science degree, you had to get through that filter, many people took it at least twice. For other reasons entirely I switched degrees, but that's another story.

My point here is that I've grown to appreciate the potential for confusion because it clearly separates those who take the time and effort to understand versus those who can't or won't. As an inspector it allows me to quickly gauge someone's level of understanding of the subject. If they don't understand the difference, I know I have to be a little bit more attentive.

Again, I'm not saying I wouldn't like to see this changed, just saying that over time it's grown on me and I'm less concerned about it.
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You make a good point. I could go down a dark road on inspections....lol In my experience, if anyone says 110/220, I am on alert and fully triggered.....
 
fastline said:
I do agree on the word "ground" sort of being loose in industry.

If I conveyed that earth is a safety circuit, that was not my intent. The 'safety' aspect is driving fault currents back to the grounded conductor to blow the OCPD. I was I guess trying to say there are two systems here, doing two different things, and two different purposes.

Where I think things get sideways is DIYers, they have the NEC book, but know very little, and honestly should NOT be touching. But they do. I think it needs to be more clear.
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I had a number of proposals, over the years, to restrict the term grounding to conductors that directly connect to a grounding electrode and use a the term "equipment bonding conductor" for the conductor that is part of the effective fault clearing path. These were all rejected.

I understand the the Canadian Code changed to equipment bonding conductor a number of years ago, and that improved the understanding of the term.

The problem is that when many people see the word grounding, all they thing of is the connection to earth.
 
don_resqcapt19 said:
I had a number of proposals, over the years, to restrict the term grounding to conductors that directly connect to a grounding electrode and use a the term "equipment bonding conductor" for the conductor that is part of the effective fault clearing path. These were all rejected.
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If they truly want accuracy the change should be accepted. Leaving this as is is just laziness.
 
fastline said:
More or less just wondering if others give this any thought? I mean, there is a whole section on this site, dedicated to just this, in which, IMO, could mean it's hard to understand, though the concepts are simple, and I believe it's because you are doing TWO things with that conductor system, and that should be more clear!
Click to expand...

it is my opinion the grounding (earthing) and bonding should be completely different code articles. Grounding would be split into 2 sections: system grounding and equipment grounding. There wouldn't have to be much under the equipment grounding section. Basically it would state that the equipment bonding system be connected to the grounding electrode system.

Also, i think the NEC seriously contributes to all the grounding myths and misunderstandings by all the garbage in there about the over-importance of the grounding electrodes and grounding electrode conductor.
 
Joe.B said:
I'm normally would agree, the terms are whack and should be changed. I will play "devils advocate" here though and offer another perspective.

When I started college I was a botany major and Chem 109 was one of the required classes that people usually took in the first year. The class was designed to be a "weeder" class, the instructor told the class on the first day that at least 60% of the class would fail out. If you were serious about getting a science degree, you had to get through that filter, many people took it at least twice. For other reasons entirely I switched degrees, but that's another story.

My point here is that I've grown to appreciate the potential for confusion because it clearly separates those who take the time and effort to understand versus those who can't or won't. As an inspector it allows me to quickly gauge someone's level of understanding of the subject. If they don't understand the difference, I know I have to be a little bit more attentive.

Again, I'm not saying I wouldn't like to see this changed, just saying that over time it's grown on me and I'm less concerned about it.
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I don't think the terms are that bad and I don't think changing them is going to fix anything, although I think the term Protective Earth is pretty cool and I would be in favor of that. I agree with you that if you get it, you get it and you can spot the guys who don't.

The problem is the Dirt Worshipers have got the whole world hung up on the idea that the most important thing is a connection to Earth. They put all sorts of emphasis on ground rods, grounding electrodes, grounding electrode conductors, better grounding, more grounding, extra grounding, it's sickening.

How about this- Instead of trying to change all the wording in the code we stop telling people that the most important thing that a light pole or a solar panel or storage shed needs is a ground rod or the cure for anything not working with their expensive piece of equipment is an extra ground rod and people will stop thinking that Grounding is the most important thing they need to do to make something safe.
 
ActionDave said:
I don't think the terms are that bad and I don't think changing them is going to fix anything, although I think the term Protective Earth is pretty cool and I would be in favor of that. I agree with you that if you get it, you get it and you can spot the guys who don't.

The problem is the Dirt Worshipers have got the whole world hung up on the idea that the most important thing is a connection to Earth. They put all sorts of emphasis on ground rods, grounding electrodes, grounding electrode conductors, better grounding, more grounding, extra grounding, it's sickening.

How about this- Instead of trying to change all the wording in the code we stop telling people that the most important thing that a light pole or a solar panel or storage shed needs is a ground rod or the cure for anything not working with their expensive piece of equipment is an extra ground rod and people will stop thinking that Grounding is the most important thing they need to do to make something safe.
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No kidding. I wish people would ask questions too, recognize that maybe they don't know everything. Get designers and builders on the same page too. Here's an example, the plans said "ground all water services":
IMG_1139.jpg
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IMG_1142.jpg
 
fastline said:
More or less just wondering if others give this any thought? I mean, there is a whole section on this site, dedicated to just this, in which, IMO, could mean it's hard to understand, though the concepts are simple, and I believe it's because you are doing TWO things with that conductor system, and that should be more clear!
Click to expand...
When I look at a electrical system for the first time, I want to know 3 things
What is the relationship of the distribution transformer (or generation source) to a grounding electrode system (GES)?
What is the relationship of exposed-conductive-parts and any equipment grounding conductors to a GES?
Which conductors if any are current carrying and grounded / neutral and what conductor provides the equipment grounding conductor / protective earth function?
To me the IEC terminology for this is very helpful, and I can answer my 3 basic questions in a simple way

In IEC terms I start at the secondary of a transformer (or generation source):
The First Letter (I or T) indicates the relationship of the distribution transformer to 'ground'.
T = direct connection of one point to earth.
I = all live parts isolated from earth, or one point connected to earth via a high impedance.

The second letter indicates the relationship of all exposed-conductive-parts and any equipment grounding conductors to a grounding electrode system.
T = direct electrical connection to a grounding electrode system independent of any other grounding electrode system.
N = direct electrical connection of a point on the transformer (neutral or phase etc) to the grounding electrode system and thus the equipment grounding conductors.

Subsequent letter with a dash - (if any) and describe the arrangement of neutral and equipment grounding conductor
S = Grounds and neutral (or grounded phase) are run separately all the way from the distribution transformer.
C = neutral (or grounded phase conductor) and equipment grounding provided by the same conductor

So a multi grounded neutral (MGN) utility system is TN-C and after the service disconnect we use a TN-S.
We can describe the entire system as TN-C-S;
T) Because at the secondary we have a direct connection of one point to a GES;
N) We have direct electrical connection of the neutral point or a line conductor to the GES and thus the equipment grounding conductors.
Then for the conductors
-C The utility neutral is combined with the equipment grounding conductor until the service disconnect.
-S After the service disconnect they are separate

If it was a SDS in a building say a 208 transformer off a 480V system the 208 system would be TN-S in IEC terms.
 
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