The article presents typical methods of connecting various types of local power sources to a medium voltage network. Describes the advantages and disadvantages of individual solutions. The authors focus particularly on the issues of power system protection, with particular emphasis on overcurrent protection (ANSI 50 and 67). The key part of the article is the presentation of the selection methodology, along with examples, of setting this type of protection for a frequently encountered case -connecting local energy sources with busbars with a line with receipts.