Expansion joints

[domnic]

I live in the mid west, how far can i run 1 1/2" aluminum conduit on roof of a building with out a expansion joint ?

 

[infinity]

Does the building have an expansion joint?

 

[Rock86]

In the 2020NEC handbook, the informational note on 300.7 suggests to multiple the values in table 352.44 by 0.40 for aluminum conduit. 352.44 tells you when you might need an expansion joint but you'd have to do more work to know what your environmental conditions.

 

[tom baker]

You need to know the max and min temps to calculate the Delta T. Then with the length you cakculate the expansion. Get the delta T from the national weather service for your area

 

[rambojoe]

We do 80', minus 90°.
Good ol arizona also requires upgrading wires for more than 20' (iirc)