Direct burial INSIDE conduit?

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mstrmp3

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We were told that the CAT 5 cable (network communications) and the 18-2 signal wire (power limited, switch leg of 24vdc 100milliamp) that runs underground had to be not only in conduit (we are using non metalic conduit to the correct depth) but also it has to be direct burial as well!

Fo rhte life of me I cannot find anything in the NEC either in 830 ot 725 or 300.5.

Is this correct? when would I ever have to use both?
 
mstrmp3 said:
We were told that the CAT 5 cable (network communications) and the 18-2 signal wire (power limited, switch leg of 24vdc 100milliamp) that runs underground had to be not only in conduit (we are using non metalic conduit to the correct depth) but also it has to be direct burial as well!

Fo rhte life of me I cannot find anything in the NEC either in 830 ot 725 or 300.5.

Is this correct? when would I ever have to use both?
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Yes, it's correct. The interior of a conduit in a damp location is itself a damp location. The wire you put in it has to be rated for that. It does not have to be rated for direct burial,but it has to be rated for outdoors.
 
2005; 300.5(B) was edited, as well and 2008;300.5(B) was edited again, and both are to be listed for "wet". IE insulated and underground - consider it wet.
 
Both the CAT 5 cable and the power limited cables are covered by Article 725. 300.5 and 300.9 do not apply to Article 725 so the NEC does not require the use of a wet location cable for these applications. However, there may be performace issues if you do not use a wet location cable.
 
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