Code Change Summary: New code language was added to specifically address the wiring methods permitted for underground service conductors.

Prior to the code change, Part III of Article 230 never mentioned what types of wiring methods could be used for underground service conductors. Now, Part III names all of the wiring methods permitted to be used for underground service conductors.

Without the code change, the user would search through Part IV or Article 230 which applies generally to all service conductors, whether overhead or underground, and select a wiring method that could be used underground based on practicality.

For example, in the 2011 NEC^®, Part IV of Article 230 would allow open wiring on insulators to be used for service conductors but an experienced electrician knows that open wiring on insulators cannot be installed underground, which by default means that the open wiring on insulators can only be used for overhead service conductors.

Now, wiring methods that cannot be used underground are not even mentioned in the new code language that pertains to underground service conductors.

Below is a preview of the NEC^®.  See the actual NEC^® text at NFPA.ORG for the complete code section. Once there, click on the “free access” tab and select the applicable year of NFPA 70 (National Electrical code).