EGC
- Thread starter domnic
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jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
See 250.118(4)
beanland
Senior Member
- Location
- Vancouver, WA
250.118
250.118
EMT is indicated to be a permitted EGC
250.118
EMT is indicated to be a permitted EGC
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- Occupation
- Licensed Electrician
Not only is it a permitted EGC it is a better EGC than any size wire you could stuff in it.
mopowr steve
Senior Member
- Location
- NW Ohio
- Occupation
- Electrical contractor
Only if all the fittings are attached properly to make assured connection to carry the fault current.
ptonsparky
Tom
- Occupation
- EC - retired
Aren't they always done that way?:roll:
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
A wire egc is also only good if the terminations are done correctly. What is the difference?
- Occupation
- Licensed Electrician
Yes, conduit used as an EGC has to be absolutely perfect. Green insulated wires can be thrown at the circuit from a hot air balloon and they will work by sheer nature of their color and composition, they are magic.
ptonsparky
Tom
- Occupation
- EC - retired
Only if they hit ground. Tangled up in a tree doesn't work.
kwired
Electron manager
- Location
- NE Nebraska
Only code compliance issue with what information has been presented in OP is raceway fill, unless it is 24 inches or less in length.
But the width of two #6 THHN is still almost the internal diameter of 1/2 EMT and would be difficult to install even in a 24 inch nipple.
But the width of two #6 THHN is still almost the internal diameter of 1/2 EMT and would be difficult to install even in a 24 inch nipple.
didn't do the math, but Table C-1 shows 2 #6s in 1/2" EMT as acceptable.
kwired
Electron manager
- Location
- NE Nebraska
I did, fill wise 2 conductors can use up to .094 sq in. 2 #6 is
two diameters of #6 totals .508 inches, inside diameter of 1/2 EMT is .622 inches, leaving .114 of free play. That may be a little more free room then I initially thought, but still pretty tight even though there is a lot of free space around those conductors, put in just one elbow and it might be nearly impossible to pull, certainly no room for any kind of pulling grip that goes around the conductors
kwired
Electron manager
- Location
- NE Nebraska
yes:ashamed1:
JFletcher
Senior Member
- Location
- Williamsburg, VA
Stagger the conductors and put the grip on the 1st one. But yeah #6 in 1/2" is tight for any distance or # of corners no matter how the pull is rigged or how much Clear Glide one uses.
EMT is a valid EGC tho as others have mentioned it has to be installed properly. Yes, a wire EGC does too but that's usually 2 terminations, not numerous pieces of conduit.
ptonsparky
Tom
- Occupation
- EC - retired
A grip for 6s? Really?
kwired
Electron manager
- Location
- NE Nebraska
Yes. I have grips small enough they could be used on just two #14's. Now two 14's is about as easy to just tie directly to a fish tape, but 5, 6, 7 even max fill on 1/2" raceway - I think it is faster to put them in the grip then to rig them up direct to a fish tape. Or if you have pull strings already in raceways it is easy to tie the grip to those even when pulling just two or three conductors.
Julius Right
Senior Member
- Occupation
- Electrical Engineer Power Station Physical Design Retired
Since NEC does not state how to use the conduit as EGC Georgia Tech Research Institute presented the research[1994] entitled:
Modeling and Testing of Steel EMT, IMC and RIGID (GRC) Conduit
https://steeltubeinstitute.org/steel-conduit/wp-content/uploads/sites/4/2014/12/GROUNDIN.pdf
According to Table 6.1 Maximum System Length (Predicted by Model for Comparison to Soares - 50 Volt Arc and 500% of Protective Device Rating) for 1/2"emt 280 ft it would be the maximum length.
Modeling and Testing of Steel EMT, IMC and RIGID (GRC) Conduit
https://steeltubeinstitute.org/steel-conduit/wp-content/uploads/sites/4/2014/12/GROUNDIN.pdf
According to Table 6.1 Maximum System Length (Predicted by Model for Comparison to Soares - 50 Volt Arc and 500% of Protective Device Rating) for 1/2"emt 280 ft it would be the maximum length.
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