Filed under schematics, this 129 KB PDF is named 60CPQ150 and gives no brand, product or board information. The code reads like a specific power component part number, with trailing digits likely indicating its rating grade. Such documents are used to confirm terminal layout, orientation and limits before replacing a part in a supply circuit. A normal PDF reader opens it. Verify the code on the physical component matches exactly, since neighbouring grades are not always interchangeable.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @cyberlanelectonik. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.