The paper presents the main specificatons of the Perm TPP and its main equipment, as well as their change resulting from the commissioning of PGU-800 power unit 4 after start-up and warranty tests at the PGU-800 start-up facility and comprehensive testing and power certification of the unit. The scope and procedure of construction, installation, and setup and adjustment and the results of the tests carried out after their completion are described. The tests demonstrated the main technical, economic, and environmental characteristics of the unit and main equipment, operational flexibility, startup duration, operating range, load change rate in this range.