Cables and Raceways Installed in shallow grooves

[sdenslow]

We cut a shallow groove in a concrete slab to add a floor outlet. We used rigid non metalic conduit. The AHJ failed the inspection quoting Table 300.5 Minimum cover requirements. He said I must have 2" of concrete cover over my conduit. I said 300.4.F Exception 1 says I can install my conduit without 2" of concrete cover. Who is correct?

 

[infinity]

T300.5 is for burial depths underground not a raceway in concrete. Here's the relevant code section.

Welcome to the Forum.

300.5 Underground Installations.
(A) Minimum Cover Requirements. Direct-buried cable
or conduit or other raceways shall be installed to meet the
minimum cover requirements of Table 300.5.

 

[sdenslow]

Confused

Confused

You said T300.5 does not apply then referred me to T300.5

 

[infinity]

You said T300.5 does not apply then referred me to T300.5

I referred to the part in bold: 300.5 Underground Installations.

 

[petersonra]

I agree with the suggestion this is not an underground installation so the table does not apply.

 

[gadfly56]

We cut a shallow groove in a concrete slab to add a floor outlet. We used rigid non metalic conduit. The AHJ failed the inspection quoting Table 300.5 Minimum cover requirements. He said I must have 2" of concrete cover over my conduit. I said 300.4.F Exception 1 says I can install my conduit without 2" of concrete cover. Who is correct?

It seems pretty clear to me that you are correct, and as infinity pointed out, Table 300.5 does not apply. I would suggest politely pointing out that the table is for underground installations and your specific installation is textbook for the exception.

 

[sdenslow]

Lost the Battle

Lost the Battle

The AHJ is Hanging His Hat on T300.5 Note 2 Raceways approved for direct burial only where concrete encased shall require a concrete envelope not less than 2" thick.

 

[infinity]

The AHJ is Hanging His Hat on T300.5 Note 2 Raceways approved for direct burial only where concrete encased shall require a concrete envelope not less than 2" thick.

What part of UNDERGROUND doesn't he understand? T300.5 is for underground. :slaphead:

 

[rcfoolinca]

Found this thread doing research on the shallow groove method. Our inspector is much worse. He is telling us that we should install the conduit UNDER the slab essentially disallowing any embedment

 

[don_resqcapt19]

Lost the Battle

Lost the Battle

The AHJ is Hanging His Hat on T300.5 Note 2 Raceways approved for direct burial only where concrete encased shall require a concrete envelope not less than 2" thick.

Rigid conduit is not a raceway "approved for direct burial only where concrete encased". I am not sure why that note is in the code. As far as I know there are no code compliant raceways that require concrete encasement when directly buried. I believe that there are some light weight non-metallic products used by the utilities that have that requirement, but those are not raceways that are permitted to be used in an NEC application.