Stand-alone UPS always clicking | Page 2

While I don’t use the same inverter, it’s my experience that the waveform output from these types of inverters when in Utility First mode is not the greatest, and it’s worse when in UPS mode than in Appliance mode. In regular SBU mode the waveform is very nice.

Whether that has any relevance to this particular issue with UPS devices for the OP, I can’t say. It didn’t for me.

My UPS’s click but only sometimes when the system is changing between Utility First and SBU modes. Choice of inverter APL or UPS mode did not cause additional clicking in our UPS units.

I only learned of this additional waveform distortion in UPS mode as it was effecting the ability of my IoTaWatt to reliably measure voltage – the waveform was falling outside of the specifications (waveform asymmetry was too high).