G2E120-AR54-43 (DigiKey part number 381-2511-ND) is a blow fan made by ebm-papst. This fan has four leads, but the initial datasheet does not describe how to hook up the part. As I have mentioned before for other parts, many companies have separate documents for operating instructions. In this instance, the link for the operating instructions for this fan is found here.
Wiring Details
The wiring details can be found on page 8 of the manual, see the diagram below.
Please note that the instructions call out on page 6 that, "if the motor run capacitor was not installed by ebm-papst, check where the information on the motor run capacitor matches the information on the name plate.” Since this item has a brown wire, this would imply that the motor run cap is not pre-installed. It is recommended to buy this separately.
Motor Run Capacitor Suggestion
Based on the specifications listed on page 5 of the operating instructions, I found a motor run capacitor that could work. The part number 32FD3706A-F-ND (32FD3706A-F) may work. This does have a higher rated voltage so the physical size may be bigger than the suggested rating in the datasheet.