Separate ground/earth wire in 1/2 EMT

[JackOfDiamonds]

At my last place I ran a 20A circuit in 1/2 EMT around the garage. I used 12 ga THHN wire but I only pulled a white and a black. I didn't pull a green ground wire through the EMT because the factory electricians at work (semiconductor industry) never did it. They said it's fine to use the EMT as the ground. I didn't pigtail-ground the receptacles either, I just left them to ground through the steel boxes through the screws and flanges.

I'm going to do the same type of thing at my new place. Since then I have heard different things about this. Some people insist I need to pull a green wire all the way through from the panel.

Others have said I don't need to do that, but I need to ground each receptacle to the boxes using apigtails and screws.

What would you do?

 

[pattenp]

You need to use self grounding receptacle or use a ground pigtail to the box if using the EMT as the ground. I choose to run a ground wire, just don't like the EMT being the grounding conductor.

 

[wyliesdiesels]

Code allows use of EMT as the grounding conductor as long as its intact end to end.

Use self grounding receptacles or pigtails as said above

BTW its not an "earth wire"

the earth does not provide a proper low impedance pathway for fault current.

 

[nadogail]

IMHO, The Code Book is the minimum standard, you may choose to do your work better than the minimum acceptable standard.

 

[wyliesdiesels]

IMHO, The Code Book is the minimum standard, you may choose to do your work better than the minimum acceptable standard.

where does the code book say that?

 

[theoldwizard1]

You need to use self grounding receptacle ... if using the EMT as the ground.

I have never seen a receptacle that is NOT "self grounding" ! Do they realy exist ?

 

[klassenl]

where does the code book say that?

All code books are a statement of minimum requirements.

 

[wyliesdiesels]

I have never seen a receptacle that is NOT "self grounding" ! Do they realy exist ?

yes they do. not all receptacles are self grounding.

All code books are a statement of minimum requirements.

again, where can this statement be found?

 

[rburke65]

I don’t know where it can be found, BUT....I thought that it was understood. If code says a 2x4 is ok, you can used a 2x6....or a 4x12. A 3/4” conduit is code, you can use a 2” hard wall. Footer 12” x8”....they won’t turn you down if yours are 24”x12”.

 

[alfredeneuman]

again, where can this statement be found?

They never say that it's a minimum
The closest they come is this (and it's second thing mentioned)
90.1(B)
Adequacy. This Code contains provisions that are considered necessary for safety.

 

[mcbane]

I once was in a dark room when a short circuit occurred on a circuit passing through an EMT conduit in that room. A protracted shower of sparks at every connection and junction box along the route of the conduit before the breaker tripped. After seeing that I have never trusted EMT with set screw couplers to be an effective ground. Running a proper ground wire is cheap.


Sent from my iPhone using The Garage Journal mobile app

 

[wyliesdiesels]

yeah i dont like set screw connectors. compression connectors are much better...

 

[mc4life27]

same i dont like using set screw connectors either but wouldn't they work better then compression terminals if using the emt as a ground since the screw would be giving a better metal to metal connection is tighten enough? since compression is just squeezing the conduit were as the screw should be putting a make in the emt? now i would always run a ground and never trust the emt as a ground either i was just thinking just as a thought

 

[sberry]

Code says it's good, science says it's the best but there are people that know more about it than those people do.

 

[dscheidt]

same i dont like using set screw connectors either but wouldn't they work better then compression terminals if using the emt as a ground since the screw would be giving a better metal to metal connection is tighten enough? since compression is just squeezing the conduit were as the screw should be putting a make in the emt? now i would always run a ground and never trust the emt as a ground either i was just thinking just as a thought

Steel set screw couplings are also more resistant to damage, and stay together better. (Cast zinc ones are not as good.) No connector style works well if the connections aren't made up tight, or if the box lock rings are loose. Set screw connectors are easier to inspect, you can at least see if the screw is tight.