EGC via EMT

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ron

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250.118 allows EMT to be the sole equipment ground conductor (EGC).

Other than making sure the typical minimum raceway installation is complete, 10' sticks and set screw couplings, is there anything else special that needs to be done. If there is an intermediate pull box or final panelboard can, are grounding bushings or anything else required for the EGC to be adequate per minimum Code requirements?
 

augie47

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Some provisions might be needed to address 250.92 or 250.97 but the same is true for other metallic raceway systems.
 

ActionDave

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250.118 allows EMT to be the sole equipment ground conductor (EGC).

Other than making sure the typical minimum raceway installation is complete, 10' sticks and set screw couplings, is there anything else special that needs to be done? ......
Yep, not much to it. Do it right and you end up with a effective, and reliable equipment ground. Heck, since most of the time EMT is used in structures with a lot of building steel, even if it's done half azzed it's still effective.
 

ron

Senior Member
Yep, not much to it. Do it right and you end up with a effective, and reliable equipment ground. Heck, since most of the time EMT is used in structures with a lot of building steel, even if it's done half azzed it's still effective.

It is surprising to me. I know it is not in the code, but I don't understand why there wouldn't be a requirement to bond at pull boxes or have a maximum conduit length that this is permitted.

For example, this NEMA paper says that 4" EMT is good up to ~350'. My install is 600', we should be required by minimum code to have an EGC conductor of some type other than the raceway.
https://www.nema.org/Technical/Documents/Bull_97_SteelConduitandEMT-ProventoMeettheNECReg_03_09.pdf
 

tom baker

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It is surprising to me. I know it is not in the code, but I don't understand why there wouldn't be a requirement to bond at pull boxes or have a maximum conduit length that this is permitted.

For example, this NEMA paper says that 4" EMT is good up to ~350'. My install is 600', we should be required by minimum code to have an EGC conductor of some type other than the raceway.
https://www.nema.org/Technical/Documents/Bull_97_SteelConduitandEMT-ProventoMeettheNECReg_03_09.pdf

You can certainly install a wire type EGC if you want. NEC is the minimum standard. There is a good software program called GEMI from the steel tube association that you can use to determine max length of raceway with out EGC.
 
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