APC Smart-UPS RT 8000VA 208V losing ground when transfering to battery

Anonymous user · ‎2021-06-27

Can anyone help.

i am using a APC Smart-UPS RT 8000VA 208V. when online it has no problems powering the utilities. when switch to battery the ground becomes live and we lose the ground therefore the equipment cannot be powered. please advise

BillP · ‎2021-06-27

I think what you're referring to is the "phantom" voltage mentioned here?

http://www.schneider-electric.us/support/index?page=content&country=ITB〈=en&locale=en_US&id=FA156549

Does that sound accurate? What type of equipment is connected to this UPS and how did you verify the voltage on the ground is causing the specific issue (versus something else that happens when the UPS goes to battery)? Is the equipment directly connected to the rear of the UPS or is there anything between the UPS and the equipment (step down transformer, PDU, etc)?

See Answer In Context

BillP · ‎2021-06-27

I think what you're referring to is the "phantom" voltage mentioned here?

http://www.schneider-electric.us/support/index?page=content&country=ITB〈=en&locale=en_US&id=FA156549

Does that sound accurate? What type of equipment is connected to this UPS and how did you verify the voltage on the ground is causing the specific issue (versus something else that happens when the UPS goes to battery)? Is the equipment directly connected to the rear of the UPS or is there anything between the UPS and the equipment (step down transformer, PDU, etc)?