History of NEC

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Natfuelbilll

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At a plant where electrical distribution system was installed ~ 1980. They did not run wire equipment grounding conductors with feeders from the 4160V/480V transformers to 480V MCCs. When was EGC brought into Code?

What is a wonderful online source to peek around NEC history?
 
If the raceways are metallic and properly installed there is no requirement for a separate wire type EC (with a few rare exceptions) even today.
 
Natfuelbilll said:
At a plant where electrical distribution system was installed ~ 1980. They did not run wire equipment grounding conductors with feeders from the 4160V/480V transformers to 480V MCCs. When was EGC brought into Code?

What is a wonderful online source to peek around NEC history?
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Here’s the first one..

archive.org

National Electrical Code, First Edition 1897 : National Board of Fire Underwriters : Free Download, Borrow, and Streaming : Internet Archive

The first edition of the NEC, published by the National Board of Fire Underwriters
archive.org
 
texie said:
If the raceways are metallic and properly installed there is no requirement for a separate wire type EC (with a few rare exceptions) even today.
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I am concerned about damage, corrosion, improper installation, vibration, moisture - so many points of failure. Can’t even test the capacity of this EGC. Scary that a metal conduit (properly installed) is sufficient. Thank you
 
Natfuelbilll said:
I am concerned about damage, corrosion, improper installation, vibration, moisture - so many points of failure. Can’t even test the capacity of this EGC. Scary that a metal conduit (properly installed) is sufficient. Thank you
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How can these non-wire equipment grounding paths get checked/verified for for current carrying capacity? Is that possible? Sure, a test for conductivity can be performed but say the conductive path relied on one last bit of metal thread in a buried conduit acting as an EGC.
 
Natfuelbilll said:
How can these non-wire equipment grounding paths get checked/verified for for current carrying capacity? Is that possible? Sure, a test for conductivity can be performed but say the conductive path relied on one last bit of metal thread in a buried conduit acting as an EGC.
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Only way I know how is via a loop impedance tester:


232 amps / 20 amps = 11.6x the handle rating is enough to trip the breaker in under 0.8 seconds.

However, this assume that there are no parallel paths in relation to the conduit itself.


In my world view, the wire type EGC is the only acceptable fault current path unless demonstrated otherwise.

Until chapter 9 can list the impedances for each conduit size, and that research is done to verify stable restive values with age I personally (in my humble world view) can not acknowledged metal raceways as a reliable fault current path.
 
Natfuelbilll said:
I am concerned about damage, corrosion, improper installation, vibration, moisture - so many points of failure. Can’t even test the capacity of this EGC. Scary that a metal conduit (properly installed) is sufficient. Thank you
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Metal conduit often can carry more current than the installed EGC can. connections is what you generally need to be concerned about, but same goes with a wire type EGC.
 
kwired said:
Metal conduit often can carry more current than the installed EGC can. connections is what you generally need to be concerned about, but same goes with a wire type EGC.
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Yeah those dreaded connections screwed in by non-wrench wielding electricians. Oh, and those listed auxiliary gutters... Wire EGC for me!
 
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