Does the National Electrical Code allow aluminum conductors to be used for underground installation?

Answer 1

You should be able to search the NEC on the internet. However, local code may play a role in whether or not you can use aluminum in an underground application. The other consideration would be whether or not it's listed as a `direct burial wire`, which is to say, is the insulation manufactured to be buried underground.

I'm not a big fan of aluminum, and if you're trying to save some money now, you'll most likely end up having to replace it within 5- 10 years. There's also been a lot of house fires attributed to aluminum wiring as it tends to overheat easier than copper.

So search the code on the internet, search your local codes and then go with copper direct burial cable anyway. You'll be happier in the long run. But yes, local amendments notwithstanding, the standard NEC does allow aluminum conductors with the proper insulation rating to be used underground. If it is installed in an underground raceway, it must be listed for wet locations, or for direct burial if buried.