UPS reporting problems with Phase Difference and Frequency

The log message

On battery power in response to frequency and phase difference

sounds like the UPS is monitoring the incoming supply for early warnings of impending failure, and one of these is  that it thinks the mains frequency / phase is not what it should be - that is to say in the 50Hz waveform, the timing of the zero crossings of successive cycles are not sufficiently repeatable.

Unless there really is a problem with the incoming mains, this is likely to be a mistake,  or locally generated interference from some nasty sizzling load that shares the supply where the suppresion has failed, or the addition of some big inverter generation locally, such as a solar panel farm or wind turbines.

Is the PFC equipment some modern fast electronic thing, or traditional banks of capacitors ? - the former may itself be a source of interference.


However, if nothing like that has been changed, it is also possible that the UPS has programmable detection sensitivity, and after the repair work it has been reset to some new levels that are a bit too keen.

The UPS makers data should tell you what the limits are, and if they are adjustable. With some actual numbers we may be able to decide if what is going in is serious or if it can be ignored without problems.

The log message

On battery power in response to frequency and phase difference

sounds like the UPS is monitoring the incoming supply for early warnings of impending failure, and one of these is  that it thinks the mains frequency / phase is not what it should be - that is to say in the 50Hz waveform, the timing of the zero crossings of successive cycles are not sufficiently repeatable.

Unless there really is a problem with the incoming mains, this is likely to be a mistake,  or locally generated interference from some nasty sizzling load that shares the supply where the suppresion has failed, or the addition of some big inverter generation locally, such as a solar panel farm or wind turbines.

Is the PFC equipment some modern fast electronic thing, or traditional banks of capacitors ? - the former may itself be a source of interference.


However, if nothing like that has been changed, it is also possible that the UPS has programmable detection sensitivity, and after the repair work it has been reset to some new levels that are a bit too keen.

The UPS makers data should tell you what the limits are, and if they are adjustable. With some actual numbers we may be able to decide if what is going in is serious or if it can be ignored without problems.