Indexed as a schematic, this 44.4 KB PDF named 180nq has the form of a power diode part number, pointing to a datasheet for a Schottky rectifier module series rather than a circuit drawing. The name has no voltage suffix, so expect a table of variants. Engineers open it to check current capability, thermal limits and terminal layout before replacing a failed module in high-current DC equipment. Any PDF viewer works; compare the complete marking on the part, as neighbouring numbers differ in rating.
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.