# 650VA UPS runs hot



## Jism (Nov 11, 2019)

I have a generic 650VA UPS hooked up behind my computer, screen and using the NIC interface to prevent any spikes and all that. Thing works fine. Can hold my computer for over 8 minutes or so. However, when it's idle, i noted that the transformer is getting around 60 to 70 degrees mark. The thing has no active cooling and more like fins in between the plastic. The screws holding the transformer are just as hot and barely good to touch.

The thing itself however, runs fine. It is only a week old. Is this something to worry about?


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## DeathtoGnomes (Nov 11, 2019)

Jism said:


> I have a generic 650VA UPS hooked up behind my computer, screen and using the NIC interface to prevent any spikes and all that. Thing works fine. Can hold my computer for over 8 minutes or so. However, when it's idle, i noted that the transformer is getting around 60 to 70 degrees mark. The thing has no active cooling and more like fins in between the plastic. The screws holding the transformer are just as hot and barely good to touch.
> 
> The thing itself however, runs fine. It is only a week old. Is this something to worry about?


with winter coming, i'd say not yet.


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## eidairaman1 (Nov 11, 2019)

Generic, send it back


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## Jism (Nov 11, 2019)

Good point. But the winters here usually dont reach anything belong 0 degrees or so.

I know transformers shoudnt run into oblivioun related to temps. At zero load it should be having zero thermals i think. Or the UPS has a very bad efficiency and is burning electricity it's not using.


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## R-T-B (Nov 28, 2019)

What brand generic?

If truly no name, yeah, it's probably a fire hazard.  If it has a name of any kind though we can at least look it up.


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## newtekie1 (Nov 28, 2019)

Jism said:


> Good point. But the winters here usually dont reach anything belong 0 degrees or so.
> 
> I know transformers shoudnt run into oblivioun related to temps. At zero load it should be having zero thermals i think. Or the UPS has a very bad efficiency and is burning electricity it's not using.



It is going to depend on how the UPS is designed.  Some use the transformer in the charge circuit for the battery.  So it will put out some heat even with no load.


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## Jism (Nov 29, 2019)

R-T-B said:


> What brand generic?
> 
> If truly no name, yeah, it's probably a fire hazard.  If it has a name of any kind though we can at least look it up.



Eurotech ups 650va. 390W constant load UPS basicly. It has a set of fuses (3x) and it even remotely ran a glue gun for over 45 minutes (15W) or so.


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## R-T-B (Nov 29, 2019)

Jism said:


> Eurotech ups 650va. 390W constant load UPS basicly. It has a set of fuses (3x) and it even remotely ran a glue gun for over 45 minutes (15W) or so.



Hmmm...  I think that brand is less offshoot than it may first appear.  I've heard the name somewhere before, at least.  Let me see what I can find on them.  Will post back after thanksgiving here (today), lol


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## Jism (Nov 29, 2019)

They wont be selling UPS's obviously that are know to cause fires. Or at least a product thats know to being faulty. They should suffice for most common household use.

You could even use it as a cheap 12V > 220V inverter if wanted.


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## R-T-B (Nov 29, 2019)

Jism said:


> They wont be selling UPS's obviously that are know to cause fires. Or at least a product thats know to being faulty. They should suffice for most common household use.
> 
> You could even use it as a cheap 12V > 220V inverter if wanted.



Yeah, Indian UPS maker is what I can dig up.  Basic units with little digital functionality but serviceable enough.

My bet is re heat:  It's good for how long the battery lasts and not much more.  Thus no battery upgrading or anything, but should work as advertised fine (unless of course, defective)


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## Jism (Nov 29, 2019)

I used it to charge, my car battery of 75ah over 20 hours, lol. And it worked perfectly fine. The battery is a 7A 12V lithium thing, just the usual. The UPS has 2x 30A fuses for proberly the 12V line, and one main 220v fuse at the back of the unit.


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## Grog6 (Nov 29, 2019)

70F or 70C?

80F is no problem, 80C is a major problem.

It's probably too small for the load.

Most good ups's are running full time, so they take over when the line voltage dies; so the full computer load is running thru the transformer and the inverter circuit, and a bit for the battery charging.


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## Jism (Nov 29, 2019)

Sometimes the UPS kicks in when there's even a one second powerdip going on in the house. I'm not sure why but usually around 03:00AM the power just drops for a tiny second leaving TV and everything else off after that. it's the reason why i bought it in the first place. I had days where i would lost my work completely after leaving the computer alone. So it's doing its job.


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## R-T-B (Nov 29, 2019)

Jism said:


> I used it to charge, my car battery of 75ah over 20 hours, lol. And it worked perfectly fine. The battery is a 7A 12V lithium thing, just the usual. The UPS has 2x 30A fuses for proberly the 12V line, and one main 220v fuse at the back of the unit.



Lol I forgot you were that guy.

Yeah, if it could do that, pretty sure it's a-ok.


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## remixedcat (Nov 29, 2019)

Not good to run things like glue guns or heaters off UPS/Power strips.


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## Jism (Dec 11, 2019)

The UPS is beeping when i'm gaming, wtf. Does this mean it's drawing more then 360 watts on avg? It has a PC + screen attached to it. When i close it down the beeping stops.


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## Grog6 (Dec 11, 2019)

Yes, that's the overload warning, most likely.

Some of them have an app that will tell you what the problem is, but I'd bet that's it.


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## Jism (Dec 11, 2019)

No shit, stops when i hit the windows key going back into windows.

This is i guess the first time in ages that i launched a game again. So this is kind of new to me. I guess the thing will be replaced soon. It's a 600VA and my system is a Ryzen 2700x / 32GB RAM / RX580 / NVME SSD and nothing else. Yes the screen is attached to the UPS as well but those are usually light weight power consumers.

Ah: the LCD consumed a 1.2A. Pulled that one out, now the gaming is perfectly fine. I guess its all on the edge for a 650VA UPS.


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## Grog6 (Dec 11, 2019)

Depends on how hard you drive it; under gaming mode, it may draw a bunch of power.

Try it without the monitor, and see.

I'd guess at ~150W minimum for the CPU, 150W for the video card, 50W for memory, so you shouldn't be pushing 500W otherwise.


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## Jism (Dec 11, 2019)

Nah it think it's within 300 ~ 400 watts of range. I can load the CPU all fully unless i start taxing the GPU as well with it.

and it only happens on heavy loaded scenes; its sporadic, but annoying as hell. I removed the LCD > that one had a power rating of 220V / 1.2A. Now it's solved.


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## Jism (Dec 27, 2019)

Yep. Just a CB20 bench puts a 83% load onto the UPS. Including gaming thats pretty much close or even over the top on what it's capable of. It is changing the voltage a bit too tho.





Starts to beep like crazy once you throw Furmark + CB together on it. I think i need a bigger one here.


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## EsaT (Jan 4, 2020)

Jism said:


> I guess its all on the edge for a 650VA UPS.


It's not 650VA UPS, but 390W UPS... Assuming honest specs.
Volt-amperes matter only with non-PFC load/in AC circuitry they don't measure actual real power, which is measured in watts.
Hence with modern PCs that VA number is completely meaningless and if UPS can provide enough watts, it can handle what little reactive power component there's present.

But because of VA number being bigger, marketroids like pushing those.
Usually "power factor" of UPS is 0.6, meaning real output power is 0.6 times VA number.
High end models usually have it higher, while in lower end UPSes it can be lower.
APC even has had some scam models with PF of 0.5 meaning their actual output power is half the advertising number.

You just need to skip that VA number completely and look for watts.
For better gaming PCs would set UPS requirement to 500W.
That also leaves some margin, because obviously it's not wise to size something for being red line loaded.
Also transfer to battery power might not be succesfull, if power draw is near full output of UPS.
Except for seamless power providing on-line/double conversion UPSes, there's short no voltage time before UPS kicks in, which no doubt causes higher momentary power draw to fill up PSU's bulk capacitor charge.




Jism said:


> I'm not sure why but usually around 03:00AM the power just drops for a tiny second leaving TV and everything else off after that.


Do you have any big factories/industrial plants nearby?
Such very high power consumers can cause hiccups into local power grid when they turn things on/off.



Jism said:


> Yep. Just a CB20 bench puts a 83% load onto the UPS. Including gaming thats pretty much close or even over the top on what it's capable of. It is changing the voltage a bit too tho.


That difference between input and output is no doubt far below measuring accuracy limit.
I mean when that whole UPS costs only fraction of higher end multimeters you can be sure there's some hefty tolerances in things.


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## Jism (Jan 4, 2020)

How is the voltage conversion done? By just the transformer? If i see the input voltage fluctuate the output voltage changes directly with that as well. So my assumption is that its a simple 'analog' voltage conversion done by the transformer. As for power outtages; i have no idea. It's just the whole house. Sometimes for one second, sometimes for 10 seconds. Always happens at night at random instances. Usually after 03:00 AM so my assumption is that it might be due to maintaince or so.


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## Grog6 (Jan 4, 2020)

It's the same as the power supply in your computer, except the output, instead of being a regulated voltage, is an Inverter circuit, running at 120/220V 50/60Hz. (depends on country what the output is)

When the input side dies, the output side is run from the batteries.

Most of the time, it echos the input voltage, but it will likely change when it goes into battery mode, depending on the quality and capacity of the ups.


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## Jism (Jan 4, 2020)

I'm talking about the Input voltage vs Output voltage, this could differ from 232V input to 235V output. It's compensating with at least 3 volts or so. It flutucates greatly as well (the output voltage together with the input voltage). Worst condition i saw was 231V > 235V, which is 4 volts. The amount of Hz also varies from 48 in worst condition to 50Hz at best. Could the UPS be compensating that as well?


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## Grog6 (Jan 4, 2020)

I think it's just that much error in the output; it only controls that in averages over a couple of seconds.

I wouldn't run an AC clock off it, lol.


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## EsaT (Jan 4, 2020)

Jism said:


> How is the voltage conversion done? By just the transformer? If i see the input voltage fluctuate the output voltage changes directly with that as well. So my assumption is that its a simple 'analog' voltage conversion done by the transformer.


"Automatic Voltage Regulator" function is typically done using specific design multi tap transformer.
Normally mains current to load just "goes through" its high/mains voltage side, while low voltage side provides power for keeping battery charged etc.
If mains voltage drops significant amount then load is switched to "higher" tap of mains voltage winding boosting voltage.
Again in case of mains voltage rising it can connect load to lower tap. ("buck" function)

Depending on price level there could be multiple taps for multiple levels of voltage boost/buck without need to switch onto battery power.
Again during blackout or when mains voltage goes too much haywire, UPS disconnects completely from mains and runs that transformer the other way using low voltage side to power high voltage side and load.
You'll recognize those UPSes from scarcity of power semiconductors and actual old fashioned transformer.
Higher end UPSes again can lack such "dumb" transformer and use more complex circuitry with whole rows of power semiconductors. With what might look like transformer being just big inductor to filter high frequency crud/smooth output.



Jism said:


> I'm talking about the Input voltage vs Output voltage, this could differ from 232V input to 235V output. It's compensating with at least 3 volts or so. It flutucates greatly as well (the output voltage together with the input voltage). Worst condition i saw was 231V > 235V, which is 4 volts. The amount of Hz also varies from 48 in worst condition to 50Hz at best. Could the UPS be compensating that as well?


Those few volt fluctuations are down to local power grid voltage varying depending on load and even voltage losses caused in wiring of your house.
Also frequency can well vary some depending on quality of local power grid.
Wouldn't expect very accurate measuring of input/output from cheap UPS.


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## Grog6 (Jan 4, 2020)

That level of tech is way out of date, and way too expensive for today.

I'd bet it's a ~150-200kHz PWM power supply, that is regulating the output to a level that approximates a 50-60Hz waveform, and filtering for that output frequency, like a 600W class D amplifier outputting 50-60Hz.

Those are really cheap these days, and the multitapped transformer you describe would be 10x the cost.

Post a pic of the transformer, and that will tell; a 600W 60Hz transformer is about 6"x6"x6"; a 600w 150kHz transformer is half the size of my fist.
A 50-60Hz transformer will be iron, a switcher will be ferrite.


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## FordGT90Concept (Jan 4, 2020)

Jism said:


> Starts to beep like crazy once you throw Furmark + CB together on it. I think i need a bigger one here.


Your assessment is correct.  It's overheating because it's overloaded.


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## Jism (Jan 4, 2020)

I'm not going to screw open my UPS now, but the transformer is'nt that 'big'. Most of the weight of the unit is caused by the battery and not transformer. If there's heat it's caused by the transformer as well.







There's 2x black mass and the rest of the wiring that comes from the transformer.



FordGT90Concept said:


> Your assessment is correct.  It's overheating because it's overloaded.



Yes, in a worst case situation it is. But when playing SOME games it's not beeping and well within the 100% load range. Once i start PUBG and in intensive scenes it start to beep.


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