Question UPS & PSU problem.

[Vky Rhodes]

Hey there,
I want to purchase a UPS for my PC.
Here's my build: https://in.pcpartpicker.com/list/9WgnsZ

I already have an inverter installed at my house but without UPS feature. It has a 150AH battery connected to it.
Now I'm looking for a UPS so that my Computer doesn't Shut off during power outage (that's obvious!).

My concern is:
Do i need to care about the back up time of the UPS? Will the UPS run through the inverter and keep my computer ON?

Please correct me, if I'm wrong here. As I don't now how all these things work.

What do I need to do in this scenario?

Inverter link: https://www.microtekdirect.com/product/microtek-digital-ups-e²925/

Please let me know
Thanks.

 

[jonnyguru]

Huh, well that's good to know, it's hard to get accurate info on specifics like that since ups waves aren't part of any reviews I can remember. It's seriously hit and miss. I know my Evga G2 550w absolutely does not like even stepped or modified square waves at all. I'm stuck with pure sinewave or nothing.

It is VERY hit or miss.

Does it matter what waveform the inverter is? I guess not. Because during outage, the power from the inverter the power will go through the UPS to PSU and then to the PC.
It's a square wave inverter by the way.

Honestly not sure what the UPS would do if fed a square wave from an inverter.

 

[Vky Rhodes]

The RMx does not have an issue with square wave.

So i can buy a square wave UPS. Won't be an issue with my Corsair RMX 650W. Right?

 

[TJ Hooker]

My issue is: I already have an inverter with a 150AH battery installed at my house but it doesn't has UPS feature. At the time of power outage, it takes about a second to provide the back up. That means my PC will shut off.
That 1 second of delay. I just need to fix this.

The device you're linking to literally has UPS in the name, why do you say "it doesn't have UPS feature"? Also, according to the specs it has a switch-over time of 15 milliseconds or less, so much less than 1 second.

 

[InvalidError]

I would choose a line interactive type of UPS. What that does is regulate the AC voltage that's input by combining it with the battery

Most consumer UPS do not use the battery at all for the "line-interactive" part of things. All they do is use a small auto-transformer (a 1kVA AVR buck/boost transformer is about the side of my fist) with 2-3 tap-changing relays to provide somewhere along the line of +20%, +10% and -10% adjustment to keep the output within 5-7% of nominal.

 

[Vky Rhodes]

The device you're linking to literally has UPS in the name, why do you say "it doesn't have UPS feature"? Also, according to the specs it has a switch-over time of 15 milliseconds or less, so much less than 1 second.

Sorry if i'm wrong.
But the reason why i'm having this confusion is that whenever there is a power outage it takes sometime (may be half of a second) to switch over. That's why I'm afraid that it may not prevent the PC from shutting down.
Also I think, it's an inverter. May be I'm wrong (again).
I'll have to confirm.

 

[TJ Hooker]

Sorry if i'm wrong.
But the reason why i'm having this confusion is that whenever there is a power outage it takes sometime (may be half of a second) to switch over. That's why I'm afraid that it may not prevent the PC from shutting down.
Also I think, it's an inverter. May be I'm wrong (again).
I'll have to confirm.

Well, every UPS has an inverter in it. I don't know what you have in your house, all I can say is that the device you're linking to is definitely a UPS.

So you're saying that if you have an outage, you actually observe that any device plugged into that UPS will power off for a seconds and then power back on after the UPS kicks in? What sort of devices have you seen this happen on?

 

[Vky Rhodes]

Well, every UPS has an inverter in it. I don't know what you have in your house, all I can say is that the device you're linking to is definitely a UPS.

So you're saying that if you have an outage, you actually observe that any device plugged into that UPS will power off for a seconds and then power back on after the UPS kicks in? What sort of devices have you seen this happen on?

Sorry i didn't mention. But I'm talking about the inverter (and not the UPS). And it's used to back up the household devices like TV, Lights, etc.

May be this comparison chart can explain about my confusion.

 

[Vky Rhodes]

Well, every UPS has an inverter in it. I don't know what you have in your house, all I can say is that the device you're linking to is definitely a UPS.

I have excatly the same device at my house. It's not an online or line interactive UPS. It works through external battery.
Does that make any difference in backing up uninterruptly?

 

[TJ Hooker]

It shouldn't matter that it's a standby-type UPS, other than that it won't necessarily protect against brownouts.

I'm just going off the written specs for that unit, which state that it should take no longer than 15 msec for it to switchover from mains to battery power in the event of an outage.

 

[Vky Rhodes]

.....all I can say is that the device you're linking to is definitely a UPS.

If you're confirming this by checking the specs then I may be wrong here confusing it with an 'inverter'.
I'll confirm it with the manufacturer.

 

[Vky Rhodes]

I'm just going off the written specs for that unit, which state that it should take no longer than 15 msec for it to switchover from mains to battery power in the event of an outage.

So as per the specs, Will it prevent my PC from shutting down in the event of an outage?

 

[Vky Rhodes]

It shouldn't matter that it's a standby-type UPS, other than that it won't necessarily protect against brownouts.

What can be done to protect from brownouts?
1. Would the PSU with active PFC be able to handle brownouts on its own leaving the only necessary addition to be a surge protector? (I have Corsair RMX650W)
or,
2. Do i need a small line interactive UPS for my PC?

 

[Vky Rhodes]

Honestly not sure what the UPS would do if fed a square wave from an inverter.

Can you please have a look at how this thread progressed?

 

[jonnyguru]

Most consumer UPS do not use the battery at all for the "line-interactive" part of things. All they do is use a small auto-transformer (a 1kVA AVR buck/boost transformer is about the side of my fist) with 2-3 tap-changing relays to provide somewhere along the line of +20%, +10% and -10% adjustment to keep the output within 5-7% of nominal.

Which is exactly what @Karadjgne said in post #8.

 

[jonnyguru]

Can you please have a look at how this thread progressed?

Your posts have created more confusion.

I agree with @TJ Hooker that the product you linked to IS a UPS. It's a 925VA UPS. Says so right in the specs.

The problem is, it's not a very good UPS! It has a "≤ 15ms" switch time. Even the cheapest, but name brand, UPS's have a switch time of 5 or 6ms. THAT is your problem.

So what you want is a UPS that can "fill that 15ms gap". That's a waste of money.

But here's the good news: That RMx has 16ms hold up time at full load (longer at lower loads), so you actually won't need anything as long as the UPS you already have switches over in less than 16ms.

 

[Karadjgne]

Line Interactive. Exactly what it says. When using the buck/boost Tx to regulate the voltages, there's potentially a loss in amperage. To maintain balance of power, the battery is used as a supplement. A regular cheapo Standby ups will actually switch to full battery when voltages reach critical low.

On-line differ in that there's no AVR circuitry needed, they use a double conversion, AC to DC then DC back to AC. The battery acting as a sink, absorbs any condition like brown-out or spike and sees constant usage vrs partial usage.