WTB Sinewave UPS Inverter, so need suggestions.

Mann said:
Does a PC loose power when it switches between mains and the inverter?
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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.
 
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rsaeon said:
I'll report back if this changes anything in the next few weeks.
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A bit late, but upsizing to a 750W power supply solved the problem entirely.

rsaeon said:
Loads like rackmount servers need line-interactive UPS because of their constant high power draw.
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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.
 
@rsaeon what should i go for, 3.5kva sinewave luminous inverter...the one you have or an 2kva/3kva Online ups getting them used.
Found a guy selling used online ups for 3.5k/4k but these are 72/96volt
Does this luminous inverter switches in less than 10ms and i may prefer it as it takes only 48v batteries and i am also thinking of getting LifePo4 battery pack or doing a diy. Initially i will be running my system only of it which has 5900x and 3070 which i will upgrade down the line and will then move this to backup the whole house in like next 1 yr as i will be shifting house.
 
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The Luminous inverter worked for me because I also oversized my power supplies, I'm using 450W units for 50-100W loads and >650W for 100-200W loads. If I used the same 450W CM MWEV2 for the 100-200W system, it would lose power and reboot during the switchover.

Online UPS would also negate the need for a stabilizer, I needed to use a stabilizer with the 3.5kVA Luminous Cruze+ because it would switch over to battery power when we had overvoltage here and that would end up draining the batteries unnecessarily.

The best option would be to have an online UPS with a very small battery (7Ah or 9Ah) connected in series with a 48V inverter with a >100Ah battery. Inverter would plug into the wall and provide extended backup while the online UPS will take care of the transient interruptions during surges and switchover that the inverter can't handle. The small battery ensures it won't overload the inverter when it's recharging.

And maybe a mainline stabilizer if high voltage is an issue in your area as it is for me. That's the setup I'm working towards, Stabilizer > Inverter > Online UPS.
 
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I want to avoid the dual backup scenario. At my current place we don't have fluctuations. Voltage vary from 220 to 250.
On my system currently i am having CM V850 psu and load i guess is around 100-200w max during general use. While gaming it may spike to 400 i guess.
Or if i really have to Will 2kva inline ups be fine. It will be rated for 1200w somewhat, considering future upgrade of system.
i don't have anything mission critical going on with pc except sometimes when i am testing some work scenarios.
 
Also check PSUs hold-up time. ATX standard is just 16ms at full load. But some PSUs have higher hold-up time like 25ms. and as @rsaeon said higher capacity PSUs can be preferred for better hold-up time for lower work loads.
 
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