This test plan is intended to provide verification for conformance of interconnection systems (ICSs) test criteria from IEEE Standard 1547-2005 [1], but applied to a testbed of several interconnected microinverters. These tests provide evaluation procedures for multi-manufacturer microinverter interoperability. The purpose of these procedures is to develop a standard method for evaluating interconnected microinverters. Utility compatibility evaluations determine the voltage and frequency operating ranges and the microinverter's response to a voltage/frequency sag or swell, and the response to an interruption in utility service.