U, V, and Y Constants for PVC Conduits in Cable Ampacity

Question: For the constants U,V and Y, PVC conduit in concrete is not an option. This is a very common duct-bank type. Am I missing something? What do you recommend we use if we have PVC in concrete?

Answer: The IEC 60287-2-1:2001 standard has no available constants for the PVC conduit. See below image:

We can see that Plastic Ducts are under consideration. However, you may use the closest option to your installation condition.




UPDATE:
The latest IEC 60287-2-1 dated 2015 has the U,V,Y constants for PVC as shown below: