plastic tubing in conduit

[GlennH]

Was at a site today that had a day tank and pump control panel for a rain collection system. The control panel inside had a conduit run to the collection tank underground with wires for the submersible pump in the tank. It also had a 1/4 in. plastic tube in the conduit for measuring the depth of the water in the tank.

Aside from conduit fill concerns is this something the NEC addresses?

 

[chris kennedy]

Is this plastic tube pneumatic in nature or does it have conductors in it?

 

[Smart $]

...

Aside from conduit fill concerns is this something the NEC addresses?

I can't think of any NEC requirement restricting the contents of any raceway to wiring only.

 

[roger]

See 300.8

Roger

 

[GlennH]

Is this plastic tube pneumatic in nature or does it have conductors in it?

No conductors in tubing, used for pressure sensor of some sort.

 

[GlennH]

See 300.8

Roger

Ahh, good one, thanks

 

[petersonra]

See 300.8

Roger

I think you can make a very good argument that this is not covered by 300.8 if it is just a sensing line.

 

[roger]

I think you can make a very good argument that this is not covered by 300.8 if it is just a sensing line.

And if you won the argument I wouldn't see a problem with it but, regardless of how well you presented your argument, I can see many if not most inspectors rejecting it based on 300.8.

Roger

 

[kwired]

I think you can make a very good argument that this is not covered by 300.8 if it is just a sensing line.

Would you still think the same way if the sensing line was sensing higher pressure liquids? It is a foreign system from the electrical system.

 

[don_resqcapt19]

If the conductors in the conduit are Article 725 conductors, then 300.8 does not apply.

 

[jumper]

If the conductors in the conduit are Article 725 conductors, then 300.8 does not apply.

Wouldn't that only apply to Class 2 and 3 conductors, and not Class 1?

725.46 Class 1 Circuit Wiring Methods. Class 1 circuits
shall be installed in accordance with Part I of Article 300
and with the wiring methods from the appropriate articles
in Chapter 3.

 

[don_resqcapt19]

Wouldn't that only apply to Class 2 and 3 conductors, and not Class 1?

725.46 Class 1 Circuit Wiring Methods. Class 1 circuits
shall be installed in accordance with Part I of Article 300
and with the wiring methods from the appropriate articles
in Chapter 3.

Yes, it appears that 300.8 would apply to a Class 1 control circuit.

 

[petersonra]

Would you still think the same way if the sensing line was sensing higher pressure liquids? It is a foreign system from the electrical system.

It is still not serving anything.

How would you feel about a sealed capillary tube in a conduit?