Question on flexible metal conduit

[ENH]

I recently took a test that had the following question and I could not find the answer for it. "What is the minimum bending radius for 1/2 flex where the final connection requires flexibility?" I checked Article 348 and Table 2, Chapter 9 "other" but could not seem to find the answer. Can anybody point me in the right direction on how to calculate this or find this answer? Thanks

 

[ptonsparky]

I believe 'flexibility ' is added for confusion. Tabe 2 has your answer, 4"

348.30 (A) exception No.2 (1) gives the max length of the unsecured FMC.

Anywhere along that unsecured length the min radius allowed is 4".

 

[ENH]

Thank you for your response but the test was multiple choice and 4" was not one of the answers to choose from.

 

[ptonsparky]

What were the choices?

 

[infinity]

Was the question about flexible metallic conduit or flexible metallic tubing. For FMT the answer is 12½". {T360.24(A)}

 

[ptonsparky]

Was the question about flexible metallic conduit or flexible metallic tubing. For FMT the answer is 12½". {T360.24(A)}

Small detail.

 

[ENH]

Hmm. I thought I remember flexible metal conduit but maybe I could have misread the question. I see the article you are referencing and its pretty clear about the minimum bending radius. Thanks for your help!

 

[infinity]

Hmm. I thought I remember flexible metal conduit but maybe I could have misread the question. I see the article you are referencing and its pretty clear about the minimum bending radius. Thanks for your help!

The two are very easily confused so if it were really about FMT that would explain why the correct answer for FMC wasn't there.

 

[don_resqcapt19]

I have never used FMT and don't think I have ever seen it on a job. However, it is required in plenum ceiling by the Chicago Electrical Code.

 

[infinity]

I have never used FMT and don't think I have ever seen it on a job. However, it is required in plenum ceiling by the Chicago Electrical Code.

The only time I've even seen it was on recessed high hat style light fixtures that were approved for use in Chicago. They were required for our application so I'm guessing someone ordered the wrong part number.

 

[augie47]

Chicago mayor likely has stock in a FMT manufacturer

 

[don_resqcapt19]

Chicago mayor likely has stock in a FMT manufacturer

They have some very different rules for "plenum" space wiring.
Like boxes with no open mounting holes and KOs that are very difficult to get out as they are not stamped as deep as a standard box. The KO remains flush with the box, not sticking out a bit like a standard box.

https://assets.gordonelectricsupply.com/tsimages/SouthwireCo_52171SVT.jpg