I HAVE ERROR MESSAGE SAYS EXTERNAL COMMUNICATION ERROR AND HAVE ERROR CODE 7-5-1
We are also having same issue with Galaxy 5500 UPS Kindly advice.............
External communication fault typically indicates a CAN communication fault between the installed UPS units, assuming there are more than one unit on site connected in parallel. If the UPS is a standalone unit then it could also be a configuration issue (i.e. unit is set to parallel mode). For in-depth troubleshooting and potential service I recommend reaching out to your local APC tech support as you might want an authorized service engineer to assess the UPS and installation.
Choose a location