I am planning on using the gray pvc conduit outside of the house for my Air-conditioning wires (240v 40A). I only see Schedule40 at the home centers. Would you explain what types and ratings of conduit can be used in each environment, i.e. for outside of the house, inside of the house, and also for educational purposes let's cover the underground installation type too.

You ask for a great deal of information, most likely not realizing what your asking for.

There are approximately a dozen different types of raceways, that would apply to your question, each with their own purpose, etc. And there are many other types that would not apply.

I could tell you to read Chapter 3 of the NEC.

Can you reduce your question to something more specific?

Unless someone else here wants to go over all the details. Hope they are prepared to write a book. Of course, that won't be necessary, as I already refer to Chapter 3 of the NEC.

I was thinking in the PVC conduit family there was only sch.40 and sch.80. So I was
Looking for details of when to use sch.40 and when to use sch80. Is there more
Options in the PVC family and where would one use it?
I can narrow down my question some more if you like.
Thanks

OK that narrows it down.

Sch 80 PVC is considered as having the same physical protection characteristics of steel rigid conduit. It is often used underground in areas where steel would normally be used, roadways, etc, and will result in labor and material cost savings.

Also used in places where exposed to corrosive conditions, chemical plants, waste treatment plants, etc. that would affect steel conduit.

It has a thicker wall, and the inside diameter is smaller than Sch 40, therefore it will allow less wire fill, has it's own Wire Fill Chart in the NEC.

See this for more info:
http://www.carlonsales.com/techinfo/faqs/FAQ-Conduit.pdf

For your purpose at home, Sch 40 is fine.

tkrussell, that's exactly what I was looking for.

Thanks
-Ab