History of grounding and bonding

[mbrooke]

When did the NEC mandate grounding of 120/240 volt services? When were EGCs required? When were motors, appliances, ect required to be grounded? What first required an EGC or neutral bond? And what is the progressive evolution of EGC requirements each year?

 

[al hildenbrand]

When did the NEC mandate grounding of 120/240 volt services? When were EGCs required? When were motors, appliances, ect required to be grounded? What first required an EGC or neutral bond? And what is the progressive evolution of EGC requirements each year?

In my opinion, these are really strange questions.

 

[mbrooke]

....

 

[mbrooke]

In my opinion, these are really strange questions.

:roll:

 

[winnie]

I don't know off the top of my head, but I can recommend a resource Soares 'Grounding and Bonding'. I don't know how things have changed in the various editions because I think they are now being written by committee and tied to the code cycle. However I recall that there was a good history of the reasons for grounding, as well as the controversies.

-Jon

 

[winnie]

I don't know off the top of my head, but I can recommend a resource Soares 'Grounding and Bonding'. I don't know how things have changed in the various editions because I think they are now being written by committee and tied to the code cycle. However I recall that there was a good history of the reasons for grounding, as well as the controversies.

-Jon

 

[mbrooke]

How far does it go into history? I keep seeing that power systems started completely sealed off from earth, then sometimes one conductor grounded, then the gradual progression of EGCs. Its kind of fascinating but historical antidotes and reasoning is rare.

 

[mbrooke]

In my opinion, these are really strange questions.

I'm not advocating the removal of EGCs, the opposite, I think anything with exposed metal including toaster ovens, DVD players and table lamps should be 3 wire.

 

[al hildenbrand]

When did the NEC mandate grounding of 120/240 volt services?

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Since you don't exclude DC, about half a century after electricity began to be used for practical purpose. And, even then, grounding of electrical services was a design decision for the next decades. And, you have to understand what "grounding" meant in those early years, which is something that is much weirder than what I understand today.​

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When were EGCs required?

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The Equipment Grounding Conductor was DEFINED in the middle of the Twentieth Century. Read the code books. There were no EGCs before they were defined.​

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When were motors, appliances, ect required to be grounded?

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That's like asking when AFCI protection was required for rooms or areas. Can't definitively be answered . . . 'cause this or that item had increasing requirements at various times and locations over the last sixty years.​

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What first required an EGC or neutral bond?

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The code, after the EGC was defined (see above).​

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And what is the progressive evolution of EGC requirements each year?

You're kidding . . . read the code books and then develop a map of when individual jurisdictions adopted that NEC statute.

 

[synchro]

Here are a few documents I found that mention early grounding and bonding:

https://books.google.com/books?id=v...q="Grounding Electrical Systems" Loyd&f=false

https://books.google.com/books?id=J...Grounding" "National Electrical Code"&f=false

https://books.google.com/books?id=D...Revision of National Electrical Code"&f=false

https://books.google.com/books?id=H...ge&q="Rule 15b" "National Electrical"&f=false

 

[mbrooke]

Since you don't exclude DC, about half a century after electricity began to be used for practical purpose. And, even then, grounding of electrical services was a design decision for the next decades. And, you have to understand what "grounding" meant in those early years, which is something that is much weirder than what I understand today.[/FONT][/LEFT]

The Equipment Grounding Conductor was DEFINED in the middle of the Twentieth Century. Read the code books. There were no EGCs before they were defined.​

Can you explain more?

I don't have the code books with me.

That's like asking when AFCI protection was required for rooms or areas. Can't definitively be answered . . . 'cause this or that item had increasing requirements at various times and locations over the last sixty years.​

It can be definitively answered much like GFCIs:

The rest can be left up to imagination because:

1) States are typically behind the latest edition of the NEC

2) Some areas did not use the NEC way back when

3) enforcement varies

4) Still things get missed- ie I've seen homes as late as 2005 have 3 wire range and dryer outlets slip by.

The code, after the EGC was defined (see above).​

You're kidding . . . read the code books and then develop a map of when individual jurisdictions adopted that NEC statute.

​

[/QUOTE]


What was the EGC called prior? "Shall be grounded"?​

 

[al hildenbrand]

Can you explain more?

I don't have the code books with me.

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Sure you do. You are on the internet doing this . . . go to NFPA's web based free access to historic NECs. Its on the page with the free online access to the 2020 NEC.​

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It can be definitively answered much like GFCIs:

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When "motors, appliances, etc., were required to be grounded" would be a monstrously large spreadsheet. I'm not interested in doing it.​

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What was the EGC called prior? "Shall be grounded"?

It wasn't called anything.

 

[al hildenbrand]

1

 

[mbrooke]

Sure you do. You are on the internet doing this . . . go to NFPA's web based free access to historic NECs. Its on the page with the free online access to the 2020 NEC.[/FONT][/LEFT]

When "motors, appliances, etc., were required to be grounded" would be a monstrously large spreadsheet. I'm not interested in doing it.​

It wasn't called anything.


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It only goes to like the 60s. Nothing from the 1900s to the 1950s.

Sparky 480 needs to scan his complete collection on of these days ​

 

[al hildenbrand]

It only goes to like the 60s. Nothing from the 1900s to the 1950s.

Look, read the literature that Synchro links to in post #10. Pay special attention to the described divergent professional opinions about grounding vs. not grounding. Grounding was mysterious.

I don't believe anything substantive relative to requiring an EGC being connected to anything with exposed conductive surface(s) exists in it. You will do well if you can substantiate it at all, with current actuarial events of injury, fire or death.

 

[petersonra]

I'm not advocating the removal of EGCs, the opposite, I think anything with exposed metal including toaster ovens, DVD players and table lamps should be 3 wire.

testing has shown that double insulated appliances are every bit as safe as grounded appliances. that is why they are allowed in certain cases.

 

[romex jockey]

IIRC , the 120 V decision came about due to Edison's 3K takes to light a filament up.

EGC's were , at first, seen as an un necessary as well as lethal entity by the then sparks who created the 'boston backwrap' , among other remedies at the time

The reality seems to be , the more MBJ's , the less effective ECG's really are

~RJ~

 

[ActionDave]

testing has shown that double insulated appliances are every bit as safe as grounded appliances. that is why they are allowed in certain cases.

I think a fella could make a case that double insulating is often better.

 

[mbrooke]

testing has shown that double insulated appliances are every bit as safe as grounded appliances. that is why they are allowed in certain cases.

But is a metal radiator, metal toaster or table lamp double insulated?

 

[mbrooke]

I think a fella could make a case that double insulating is often better.

Like when a 19920 volt wire touches the LV