grounding bushing for GEC

[DENN M.]

I've run into a couple inspectors lately who insist that in accordance with 250-64(e), an armored ground wire must be installed with a grounding bushing. Is this the proper interpretation, and if not, what can I use to dispute their interpretation?

 

[infinity]

What part of 250-64(e) do they think is applicable? And what code cycle are you under? The (-) went out many cycles ago.

Welcome to the forum.

 

[ceb58]

I've run into a couple inspectors lately who insist that in accordance with 250-64(e), an armored ground wire must be installed with a grounding bushing. Is this the proper interpretation, and if not, what can I use to dispute their interpretation?

You cant dispute it. Use PVC to run the GEC in and you wont have this problem.

 

[DARUSA]

250.64 e

250.64 e

Bonding of the metal raceway that contains a grounding electrode conductor to the conductor at both ends , as required by 250.64 E

 

[DENN M.]

I guess I'm questioning whether or not the armor is actually considered a raceway when it is not actually able to be used as a raceway by itself. can the sheathing be pulled off and used as 3/8 in. flex? Legally?

 

[eprice]

I guess I'm questioning whether or not the armor is actually considered a raceway when it is not actually able to be used as a raceway by itself. can the sheathing be pulled off and used as 3/8 in. flex? Legally?

Hmmm, lets make sure we're all on the same page here. Are you talking about a grounding electrode conductor or are you talking about the equipment grounding conductor in a circuit?

 

[cripple]

grounding bushing for GEC

250-64(e) first appeared as a code change in 1999, this requirement was located in 250-71(a)(3) of 1996 NEC. The requirement does state that the following: . Ferrous metal enclosures for grounding electrode conductors shall be electrically continuous from the point of attachment to cabinets or equipment to the grounding electrode and shall be securely fastened to the ground clamp or fitting. It does require the bonding raceway and cable armor, which encloses the grounding electrode conductor. In my opinion the inspector is correct in his interpretation.

 

[infinity]

250-64(e) first appeared as a code change in 1999, this requirement was located in 250-71(a)(3) of 1996 NEC. The requirement does state that the following: . Ferrous metal enclosures for grounding electrode conductors shall be electrically continuous from the point of attachment to cabinets or equipment to the grounding electrode and shall be securely fastened to the ground clamp or fitting. It does require the bonding raceway and cable armor, which encloses the grounding electrode conductor. In my opinion the inspector is correct in his interpretation.

Here is what the 2008 says:

(E) Enclosures for Grounding Electrode Conductors. Ferrous metal enclosures for grounding electrode conductors shall be electrically continuous from the point of attachment to cabinets or equipment to the grounding electrode and shall be securely fastened to the ground clamp or fitting. Nonferrous metal enclosures shall not be required to be electrically continuous. Ferrous metal enclosures that are not physically continuous from cabinets or equipment to the grounding electrode shall be made electrically continuous by bonding each end of the raceway or enclosure to the grounding electrode conductor. Bonding shall apply at each end and to all intervening ferrous raceways, boxes, and enclosures between the cabinets or equipment and the grounding electrode. The bonding jumper for a grounding electrode conductor raceway or cable armor shall be the same size as, or larger than, the enclosed grounding electrode conductor. Where a raceway is used as protection for a grounding electrode conductor, the installation shall comply with the requirements of the appropriate raceway article.

So if the metal cable armor is connected to the grounded enclosure with the proper fitting why is a bonding bushing required? The cable armor is not a raceway so the last sentence does not apply.

 

[DENN M.]

Thanks Rob. I believe you're right.

 

[cripple]

Here is what the 2008 says:

So if the metal cable armor is connected to the grounded enclosure with the proper fitting why is a bonding bushing required?

In the 2005 the requirement for sizing the bonding jumper was a Code change. Prior to 2005 no approved bonding method was stated in the general rule, it now state how the bonding jumper for raceway and cable armor is be sized. The statement made no mention of proper or approved fitting or when using or if using a wire type bonding jumper. If proper or approved fitting were acceptable it would reference 250.94 for service bonding.


The cable armor is not a raceway so the last sentence does not apply.

As for the last sentence I think we all know should know the different between cable armor and a raceway. But we should also know that the last sentence is refereeing to all the installation requirement of the appropriate raceway article.

With that said the inspector?s interpretation is correct.

 

[Dennis Alwon]

I also believe a bonding bushing should be used as you don't want a choke effect on the GEC. Bonding the armored cable would alleviate that issue. I agree the code says raceway but....