Weidmueller ES APG 80 AEH 150

ES APG 80 AEH 150  likely refers to a specific product or component.  "APG" could be an abbreviation for a company, product line, or perhaps even a type of gear or mechanism (like an "automatic phase generator" or similar). The "80" probably signifies a size, rating, version, or other numerical characteristic of the product. To find out exactly what APG 80 is, you'll need to search online using that term and any other relevant keywords you have (like the industry it's used in or the type of equipment it's part of).