250.118 - using emt conduit as a ground

[Besoeker3]

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...

[480sparky]

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...

Man..... you're OLD!!!!!!!

[Besoeker3]

Man..... you're OLD!!!!!!!

What did you say????

[peter d]

If the raceway is so good as an EGC why is there ever a need for redundant grounding? Needs to be extra good?

Pfft, not only do I run a ground on the inside, I run one on the outside as well.

[kec]

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.

[kwired]

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.

And also seen 1/2 FMC fittings used for 3/4 EMT. Works great when you ran 3/4 but didn't know how to enlarge a 1/2 KO, or if you needed a 90 degree connector

[LarryFine]

. . . Ive come across installations [done by others] with duck tape used for couplings.

I'm sure the duct tape was put on to facilitate using vacuum to pull in string to pull in a pull rope.

[retirede]

I'm sure the duct tape was put on to facilitate using vacuum to pull in string to pull in a pull rope.

It could have been duck tape:

https://www.duckbrand.com

[LarryFine]

It could have been duck tape:

https://www.duckbrand.com

Oh, you're quackers! (yes, I know about that brand)

[electrofelon]

I'm sure the duct tape was put on to facilitate using vacuum to pull in string to pull in a pull rope.

I have seen it used to (presumably) make fittings raintight

[480sparky]

What did you say????

Speak up, sonny. I kint hear ya.

Now, get off my lawn!!!!

[DBoone]

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.

Always use aluminum foil duct tape, maintains continuity....good to go

[MAC702]

Always use aluminum foil duct tape, maintains continuity....good to go

Brilliant, literally!

[Adamjamma]

It comes down to installation... in UK and USA I don’t run into much rusted out emt, so the use of it for ground is fine. In Caribbean I run into a lot of rusted out emt with no continuity of ground... so in Caribbean I always add a ground conductor...

[petersonra]

It comes down to installation... in UK and USA I don’t run into much rusted out emt, so the use of it for ground is fine. In Caribbean I run into a lot of rusted out emt with no continuity of ground... so in Caribbean I always add a ground conductor...

It seems to me that if the EMT is rusting out it is not suitable to use it at all in that location.