Was steel flex ever acceptable for a ground

[220/221]

Is steel flex an acceptable ground? (over 6')

Was it ever?


Apartments built in early 60's wired with steel flex and #12 thw.

All outlets are grounded type. I BELIEVE someone at some point has changed them.....maybe in the 70's???

Generally when I see THW, it goes back to the 2 prong outlet era.


I hate getting involved in this crap.

 

[tmbrk]

Maybe this will help?

http://www.iaei.org/subscriber/magazine/01_e/ul.htm

Specifically AC type cable.

 

[infinity]

I've seen this too in older homes. I'm guessing that when it was installed non grounding devices were being used so it didn't really matter. For the record, type AC cable is not the same as steel flex or flexible metallic conduit.

 

[peter d]

Allegedly the infamous MGM Grand fire started from a poorly bonded piece of flex that was being used as the ground.

 

[pbeasley]

Allegedly the infamous MGM Grand fire started from a poorly bonded piece of flex that was being used as the ground.

I thought it was caused by overheating theatrical dimmer racks in the show space. They were an experiment in plastic that went very wrong on many installs..

 

[don_resqcapt19]

I thought it was caused by overheating theatrical dimmer racks in the show space. They were an experiment in plastic that went very wrong on many installs..

No, it was a flex connection on a refrigeration display case for one of the restaurants.

 

[cadishead]

Steel Flex

Steel Flex

Is steel flex an acceptable ground? (over 6')

Was it ever?


Apartments built in early 60's wired with steel flex and #12 thw.

All outlets are grounded type. I BELIEVE someone at some point has changed them.....maybe in the 70's???

Generally when I see THW, it goes back to the 2 prong outlet era.


I hate getting involved in this crap.

Yes you are correct. Of course these days a green conductor must be installed along with the other conductors. Many cities in Southern California had their own codes and used the NEC and State codes in part but not in their entirety. The City of Los Angeles required the flex to be square cut.
These days most cities allow romex in place of flex for single family homes and apartments up to so many units. I hope this helps.

Cadishead