Question Does Line Interactive UPS damage the PSU?

[blueskyx5]

I am thinking of buying a UPS for voltage fluctuation risks. But it is claimed that Line interactive UPS can damage the PSU because they use Simulated sine wave. (Although it may not cause any damage, it is claimed that the PSU will be subject to additional load as it will re-regulate the simulated wave). Could this be true?

The second problem is that I am using a 750W Cooler Master 80+ plus bronze certified psu. Can these 80+ bronze certified power supplies withstand voltage fluctuations in the mains supply and send them to the equipment by adjusting them to the appropriate level? Because if it can do that then I won't need to buy UPS. (Because my goal is to prevent hardware damage by preventing voltage fluctuations, not to prevent data loss or sudden power outages.)

 

[Eximo]

Ideally any UPS or line conditioner you get will have a true sine wave output.

Simulated sine wave just means the AC produced isn't very good, which puts more strain on the capacitors in the PSU. Once a suitable high voltage DC is produced, then you have your 12V, 5V, and 3.3V outputs. On high end PSUs these are all DC-DC converters which do a pretty good job of removing ripple and the like. The 12V particularly gets stepped down again by the VRMs in the system to make the 1ish volts that chips run at.

Old group regulated PSUs are basically still producing the 12V directly off the mains power, just stepped down through a transformer, and smoothed out by a smaller capacitor. Even older supplies this applied to 5V and 3.3V as well.

I wouldn't call the 750W Cooler Master 80+ Bronze the best choice ever.

Essentially the larger the PSU the longer a PSU can provide stable power to your system, because of the capacitors. So a large 1000W gold rated unit it will be able to handle grid power fluctuations a little better than smaller units.

A line conditioner basically just smooths out the incoming AC and offers protection against sags, surges, and the like, but offers no zero power backup.

A UPS basically produces AC from a DC battery. Pure sine wave means the DC chopping is very well done, vs cruder, cheaper circuits that make a messy sine wave.

Line interactive just refers to a UPS that also acts as a line conditioner, effectively, so that it doesn't switch to backup power with slight fluctuations, only when power disappears for a certain time frame. (I had an old UPS that would active anytime the air conditioner came on, for example)

 

[blueskyx5]

Ideally any UPS or line conditioner you get will have a true sine wave output.

Simulated sine wave just means the AC produced isn't very good, which puts more strain on the capacitors in the PSU. Once a suitable high voltage DC is produced, then you have your 12V, 5V, and 3.3V outputs. On high end PSUs these are all DC-DC converters which do a pretty good job of removing ripple and the like. The 12V particularly gets stepped down again by the VRMs in the system to make the 1ish volts that chips run at.

Old group regulated PSUs are basically still producing the 12V directly off the mains power, just stepped down through a transformer, and smoothed out by a smaller capacitor. Even older supplies this applied to 5V and 3.3V as well.

I wouldn't call the 750W Cooler Master 80+ Bronze the best choice ever.

Essentially the larger the PSU the longer a PSU can provide stable power to your system, because of the capacitors. So a large 1000W gold rated unit it will be able to handle grid power fluctuations a little better than smaller units.

A line conditioner basically just smooths out the incoming AC and offers protection against sags, surges, and the like, but offers no zero power backup.

A UPS basically produces AC from a DC battery. Pure sine wave means the DC chopping is very well done, vs cruder, cheaper circuits that make a messy sine wave.

Line interactive just refers to a UPS that also acts as a line conditioner, effectively, so that it doesn't switch to backup power with slight fluctuations, only when power disappears for a certain time frame. (I had an old UPS that would active anytime the air conditioner came on, for example)

In that case, the UPS in question will put extra load on the PSU. (If the UPS is not a Pure Sine Wave generating UPS) Even if a 750W Bronze certified PSU isn't the best, it will still withstand power surges and regulate voltage fluctuations better than older PSUs from the 90s and 2000s. Am I understanding correctly?

 

[Eximo]

In that case, the UPS in question will put extra load on the PSU. (If the UPS is not a Pure Sine Wave generating UPS) Even if a 750W Bronze certified PSU isn't the best, it will still withstand power surges and regulate voltage fluctuations better than older PSUs from the 90s and 2000s. Am I understanding correctly?

I would not invest in any hardware that can't produce a 'pure' sine wave. Just going to be a lower quality device in general.

But then I also wouldn't pick out that PSU for any expensive hardware.

I can not explain the difference a good PSU makes in system stability. As soon as I got interested in the topic, computer crashes I experienced went from several times a month to once or less a year.

Cooler Master MWE is worth a look if that is available to you. Around that price point should also be Thermaltake Toughpower series. Corsair's RM750e and 850e aren't amazing, but still better than the bronze units from Cooler Master.

Now generally the 220-250V only units that Cooler Master makes are a bit better than the 100-250V units they supply elsewhere, but that is just because they can be built simpler. Generally true of all such units, but also means they don't have to try quite as hard to get that 80 Plus certification.

 

[blueskyx5]

I would not invest in any hardware that can't produce a 'pure' sine wave. Just going to be a lower quality device in general.

But then I also wouldn't pick out that PSU for any expensive hardware.

I can not explain the difference a good PSU makes in system stability. As soon as I got interested in the topic, computer crashes I experienced went from several times a month to once or less a year.

Cooler Master MWE is worth a look if that is available to you. Around that price point should also be Thermaltake Toughpower series. Corsair's RM750e and 850e aren't amazing, but still better than the bronze units from Cooler Master.

Now generally the 220-250V only units that Cooler Master makes are a bit better than the 100-250V units they supply elsewhere, but that is just because they can be built simpler. Generally true of all such units, but also means they don't have to try quite as hard to get that 80 Plus certification.

Thanks for the details... What actually surprises me is that we used the poor quality, unbranded PSUs we used in the 2000s for years and nothing happened against electrical voltage fluctuations. I mean the old primitive psu's didn't cause any problems in this regard. Now, the Cooler Master 750W 80+ Bronze certified PSU should be much better than them. Yes, it is not the best at the moment, but we cannot say that it is a primitive psu.

Here's what surprises me: Could we be exaggerating a little? Even though our systems are different, we are all using new technologies. We never had any problems even with the old psu's. Aren't these psu's supposed to actually do a better job?

 

[Eximo]

Not sure how your 2000s went, but I had many an unstable system back then. It was still possible to get a better than average PSU, even then and I did have one that lasted many years, though I do recall replacing the fan.

The farther back you go the lower power the systems were and the higher voltage they ran at and the slower they were. Drives particularly used a lot of 5V and 3.3V, these days we don't even have the drives. Switching frequencies were lower, all kinds of factors.

250-350W used to be considered a high end power supply. 400W and 500W was massive. CPUs had a single core running at 1Ghz or so, graphics cards relied on slot power, had no fans. (Go back a little further and the CPUs had no fans)
At the high end a single 4-pin Molex for a GPU. Now you can have a CPU alone pull 300W at 12V, and a GPU pulling 600W at the same time. Even mid-range systems can see 100W-150W from a CPU and 250-300W from a GPU. 750W is good for that, but a bronze unit is going to have about 50% more waste heat as a gold rated unit, which reduces its lifespan. And that is assuming you are in the sweet spot for the efficiency curve.

Modern systems fluctuate rapidly in their power demands. Group regulated power supplies can get unbalanced under varying load conditions and you can see extra high voltage well outside the ATX spec as well as lower voltage outputs. There are still group regulated PSUs on the market, easily identified by their high 5V and 3.3V outputs and often sold with the express purpose of gaming in mind.