Application Question Breakdown: "What is the point of interconnection compliance method in busbar #X?"
Application Question:
Where do I find this information on the plan set?
Typically, you'll find this information on a copy of your single line diagram near the service panel. It will references the back-feed protection for the busbar under NEC Article 705.12 and 705.13.
The note may not be as prevalent as the example above, but will most likely mention one of the following:
NEC 705.12(B)(2) "120% rule" example:
NEC 705.12(B)(3) "Sum of Breakers rule" example:
NEC 705.13 "Power Control System (PCS)" example(s):
What error message would I receive if I entered this incorrectly?
Typically, you'll receive the following error if the incorrect interconnection compliance method is selected:
R749: 120% rule Your main breaker rating plus 125% of your power production source(s) continuous output current rating is larger than 120% of your busbar rating. Either choose a larger busbar rating, or make the sum of your main breaker and your power production source(s) smaller.
Further Reading
What is the point of interconnection compliance method and what does it mean?