You might want to rethink the part about the residential services never going over 10 kA. In the front lot services of today and zero lot line construction, the transformers are setting close to the garage (you know, where you are fond of placing the service [Linked Image] ). We are serving a lot of subdivisions that are mostly electric heat with 50 and 75 kVA transformers and either 4/0 or 500 Al. triplex service laterals. The homes that are next to the transformers get 20 to 30 foot service laterals. They have a problem.

Charlie Eldridge, Indianapolis Utility Power Guy