250.118 - using emt conduit as a ground

difowler1

Senior Member
Looks like it's okay in 250.118 to use emt as a ground. Is it also code to run subpanel feeder circuit without a equipment grounding conductor as long as the wires are within emt pipe the whole way?
 

packersparky

Senior Member
To add to Roger's response, many studies have shown that a metallic raceway performs better at clearing a fault than a wire type equipment grounding conductor.
 

infinity

Moderator
Staff member
We use EMT as an EGC all of the time unless someone is paying for a wire type EGC in the raceway.
 

peter d

Senior Member
We use EMT as an EGC all of the time unless someone is paying for a wire type EGC in the raceway.
:thumbsup:

I don't get the obsession with wire EGC's. I always encounter EMT installations done from the 1960's to the 1980's and it never had a separate ground wire. Now it does. :roll:
 

MAC702

Senior Member
just seems weird, but ok. thanks
It did to me, too, because all my apprenticeship years were for places that spec'd the wire EGC, so it was normal for me. Now, people pay me to just make it work, and I'm the one buying and pulling the wire, so....
 

kwired

Electron manager
:thumbsup:

I don't get the obsession with wire EGC's. I always encounter EMT installations done from the 1960's to the 1980's and it never had a separate ground wire. Now it does. :roll:
Seen many from the time period you mentioned with poorly supported raceway contributing to broken fittings resulting in loss of EGC, also seen loose set screws or compression nuts, but that is all workmanship issues more than anything IMO. Have seen poorly made up EGC's in cable wiring methods as well - open continuity is still open continuity.

I do a lot of grain storage bins and handling equipment. Generally all steel structures and equipment. I do run EGC's in flexible conduits or in any non metallic raceways (which is usually just underground raceways in these applications) but see running any wire EGC in most of said systems as pointless, the equipment/structures are very effective fault return path, and usually more effective than my raceways, so if a fitting didn't get tightened it doesn't really matter much from equipment grounding perspective.
 

jap

Senior Member
Pulling a wire type EGC is more about a backup or assured bonding.

Much like a safety chain installed on a perfectly supported pendant fixture.

JAP>
 

jap

Senior Member
Plus, dropping that one conductor when emt is used, helps somewhat for the added conductors we now have to add for MWBC's that we didn't used to have to install.

That is for us old dogs that always used MWBC's and now don't like tying individual circuit handles together. :p

JAP>
 

kwired

Electron manager
Pulling a wire type EGC is more about a backup or assured bonding.

Much like a safety chain installed on a perfectly supported pendant fixture.

JAP>
Which NEC only requires additional paths for certain art 517 applications (could be other specific sections but am not aware of any), outside of that it is a design decision.
 

infinity

Moderator
Staff member
Which NEC only requires additional paths for certain art 517 applications (could be other specific sections but am not aware of any), outside of that it is a design decision.
If the raceway is so good as an EGC why is there ever a need for redundant grounding? Needs to be extra good? :)
 

kwired

Electron manager
If the raceway is so good as an EGC why is there ever a need for redundant grounding? Needs to be extra good? :)
I didn't write the rule, apparently it knows when it is in a health care facility and gets nervous or something:)
 

Besoeker3

Senior Member
Haven't seen EMT used for any installations since I was doing my apprenticeship in the 1840s....and even then we had to run a separate earth (grounding) conductor... :cool:
 

kec

Member
Seen many from the time period you mentioned with poorly supported raceway contributing to broken fittings resulting in loss of EGC, also seen loose set screws or compression nuts, but that is all workmanship issues more than anything IMO. Have seen poorly made up EGC's in cable wiring methods as well - open continuity is still open continuity.

I do a lot of grain storage bins and handling equipment. Generally all steel structures and equipment. I do run EGC's in flexible conduits or in any non metallic raceways (which is usually just underground raceways in these applications) but see running any wire EGC in most of said systems as pointless, the equipment/structures are very effective fault return path, and usually more effective than my raceways, so if a fitting didn't get tightened it doesn't really matter much from equipment grounding perspective.
Agree, if set screws are tight then your are good to go, but Ive come across installations [done by others] with duck tape used for couplings. :eek:hmy:
 
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