Steel Flex Conduit as ground path

[Dustin Foelber]

I have a project in which we are rewiring a 12 unit apt complex. The engineered drawings call for us to replace the single phase 240/120 sub-panel yet calls for the sub-feed to remain existing. The existing sub-feed is a 125A feed consisting of (3) 1/0 aluminum conductors in a steel flex conduit. I have landed this in our new panels and installed a ground bushing from the flex connector to our panel ground bus bar. I am not sure if there is a violation in place. Drawings call for sub-feed to remain existing. Can the inspector require us to attempt to pull in a ground conductor or is ok to let steel flex remain the pathway.

 

[tom baker]

Is the wiring method Steel MC, AC or Flexible Metal Conduit?
"Steel Flex" is not specific enough, as steel MC or AC would be allowed.

 

[weressl]

I have a project in which we are rewiring a 12 unit apt complex. The engineered drawings call for us to replace the single phase 240/120 sub-panel yet calls for the sub-feed to remain existing. The existing sub-feed is a 125A feed consisting of (3) 1/0 aluminum conductors in a steel flex conduit. I have landed this in our new panels and installed a ground bushing from the flex connector to our panel ground bus bar. I am not sure if there is a violation in place. Drawings call for sub-feed to remain existing. Can the inspector require us to attempt to pull in a ground conductor or is ok to let steel flex remain the pathway.

The "flex" portion would need to be specifically rated as suitable for being an EGC.

 

[CONDUIT]

Read 250.118 (5). Overcurrent Device not to exceed 20 amps. Combined length of conduit not to exceed 6 feet.