Issue:

Why do I measure voltage on the outputs of my UPS even though the output is turned off?
Why do I measure voltage on the input when the UPS is on battery?

Product Line:

Smart-UPS

Environment:

All models, All Serial Numbers

Cause:

Phantom voltage can sometimes be detected with a voltmeter on the output of the UPS even though the UPS output is switched off.
This voltage is not actually present, and If a load were to be applied, the voltage will immediately collapse.

This same phenomenon can be seen on the input of a UPS when it is on battery. This would also collapse if any load were to be applied. All Smart-UPS incorporate backfeed protection and meet UL specifications for such.

Resolution:

This is normal operation and will not affect any equipment connected to the UPS.