WTB Sinewave UPS Inverter, so need suggestions.

[rsaeon]

Does a PC loose power when it switches between mains and the inverter?

Today, one of my systems was at full cpu load when the distribution transformer nearby was disconnected and reconnected, so power went out for a couple of seconds. This system lost power in the time it took for the inverter to switch to battery, in that fraction of a second.

I believe this happened because of two factors:

1. This particular system has a modestly sized power supply (450w for a processor that can pull 190w at full load) – this may not have happened with the larger/better capacitors of a higher end power supply. Six other systems which have the same power supply, but lower TDP processors were not affected.
   
   
2. The inverter was set to unregulated mode, this means the inverter wouldn't switch to battery until the voltage dropped to below 100v, and it probably switches to battery slower in this mode.

I've now switched the inverter to regulated mode. I should have done this from the start, but I didn't because I thought it would make the batteries last longer.

I'll report back if this changes anything in the next few weeks.

 

[rsaeon]

I'll report back if this changes anything in the next few weeks.

A bit late, but upsizing to a 750W power supply solved the problem entirely.

Loads like rackmount servers need line-interactive UPS because of their constant high power draw.

Correcting myself here, most budget UPS are line-interactive, they turn on and off depending on voltage supply and fluctuations. The more expensive ones are called Online UPS, they're always online/powered from batteries, but the charging circuit is oversized to supply power to the load and to charge the batteries at the same time, so the batteries are never actually disconnected.