I have spend the past 20 years researching and testing the concepts of what others have written as it relates to Grounding. I have found that much of what I learned about grounding is not really accurate, at least not in relationship to premises wiring within the scope of the National Electrical Code.

This weekend I made lots of new discoveries based on some old historical papers that I received. I think I found the origination of the 25 ohm resistance for a ground rod, why a 6 AWG wire is used for a ground rod, and about where this concept of zero reference might have originated. By the way, the resistance of 8 AWG run seven miles at 25C is 24.64 ohms.

Click here to download [PDF 960KB ] "Transactions of the American Institute of Electrical Engineers", "EARTH WIRES OR THE EARTH AS AN ELECTRIC COMPLETER."

Oh yea, Thomas A. Edison was heavily involved with the telegraphic system (before the light bulb), and he invented the fire alarm mechanism and signaling apparatus https://invention.smithsonian.org/resources/fa_wu_container12.aspx.

Now the plot thickens… the Telegraphic industry uses the earth as a return conductor and Edison is involved in the Telegraphic industry. According to a good buddy of mine (Don Zipse), when Thomas Alva Edison started his electric illuminating company and began the electrical distribution system, he used the earth for the return conductor. This uncontrolled flow of electric current over the earth resulted in shocking horses and his employees as they dug along side of the underground distribution system. Horse pulled traction companies' employees working on the tracks received electric shocks, especially when separating the track joints.

In addition, based on original Ralph Lee (great engineer) writing, I figured out what the Code means about 'stabilize system voltage to earth during normal operation [250.4(A)(1)]. I'm so glad because nobody I know what this mean anyway. By the way it has to do with electric utilities and ungrounded systems, with miles and miles of overhead conductors, not premises wiring! So basically it's irrelevant.

Unrelated to all of this, but just important (at least to me), I also figured out how a ground rod (earthing) could be used to reduce voltage on the metal case of a transformer that were installed in the 1890's. So basically grounding (earthing) the case of a metal transformer is just something we do based on conditions from over 100 years ago that don't apply today.

Then in the middle of the night, I figured out how placing a ground wire (connected to a ground rod) in a plastic animal water trough could be used to reduce voltage in the water so that the animals would drink it!

But basically for today's grounding (earthing, such as driving a ground rod) still doesn't do anything we (or at least I) thought it did to make anything safe in a home, establish a zero reference, or any of the other myths we carry on (https://www.mikeholt.com/mhgvb).

I'm currently working on a new book that probably will be titled Grounding Theory and the Real History of Grounding. It will be out in time for my Grounding versus Bonding seminars this fall https://www.mikeholt.com/seminarnew.php?id=2005#October.

Oh what a great week of discovery.

God Bless,

Mike Holt

HELP: I need some help to understand the wiring of the telegraph system in the 1800's. What voltage did they transmit? What was the local system voltage? What was a typical distance of transmission? What was the transmission load (watts) required needed to operate the telegraph? Do you know of any wiring diagrams?

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October
TOPIC	LOCATION	SPONSOR	INFORMATION
October 10th thru October 11st Mike Holt/EC&M/Leviton: Grounding versus Bonding Boston, MA Boston Convention & Exhibition Center 415 Summer Street (617) 954-2000 Mike Holt Enterprises, EC&M Magazine & Leviton Email Sarina Snow Phone: (888) 632-2633 [ Download Brochure ] [ Preview Video ] [ Seminar Details ] [ Order Both Days ]
October 18th thru October 19th Mike Holt/EC&M/Leviton: Grounding versus Bonding Philadelphia, PA Pennsylvania Convention Center 1101 Arch St. (215) 418-4700 Mike Holt Enterprises, EC&M magazine & Leviton Email Sarina Snow Phone: (888) 632-2633 [ Download Brochure ] [ Preview Video ] [ Seminar Details ] [ Order Both Days ]

November
TOPIC	LOCATION	SPONSOR	INFORMATION
November 9th thru November 10th Mike Holt/EC&M/Leviton: Grounding versus Bonding Seattle, WA Meydenbauer Center 11100 NE 6th Street (425) 637-1020 Mike Holt Enterprises, EC&M magazine & Leviton Email Sarina Snow Phone: (888) 632-2633 [ Download Brochure ] [ Preview Video ] [ Seminar Details ] [ Order Both Days ]
November 16th thru November 17th Mike Holt/EC&M/Leviton: Grounding versus Bonding Chicago, IL Midwest Conference Center 401 W Lake St Northlake, IL Outside Chicago - 7 Miles from Ohare Mike Holt Enterprises, EC&M magazine & Leviton Email Sarina Snow Phone: (888) 632-2633 [ Download Brochure ] [ Preview Video ] [ Seminar Details ] [ Order Both Days ]