# What AC input voltage range can be considered safe for a pc?



## quicky008 (Dec 4, 2016)

In India the voltage of the mains power usually ranges from 200-240V(under normal circumstances) and most computers today(especially devices like PSU,monitors etc) are rated to work well when the input voltage is within 200-230 Volts.In cities the mains voltage is generally found to be within acceptable limits and rarely does it drop below or exceed the normal levels.

However in rural areas voltage often fluctuates greatly and even in normal scenarios the input voltage is found to be well above or below the normal range.What i'd like to know is will it be safe for a user to operate electronic equipments(like PCs,laptops etc) that are designed to work at 230V when the mains voltage is slightly greater (or lower)than normal? Is a computer likely to sustain any damage when its operated on a mains power supply that's delivering either 250-270 V or 180-200V?How much variation in input voltage can a computer and its peripherals tolerate nowadays? 

I have an APC ups(BX 600C-in) that's supposedly equipped with an AVR-however i've observed that even when the mains voltage rises to around 250-260V it does nothing ie it doesn't attempt to step it down to a safe operating range(ie to 200-230V).Does that mean the UPS is working correctly and there'd be no problems if the connected equipments are operated at ~250V?

I'd be much obliged if someone could answer my queries and shed some light on this matter,thanks.


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## bssunilreddy (Dec 4, 2016)

How do you know that voltage rises when using an UPS?

What are you using for calculating such voltages?

I have APC 1000VA UPS( BR1000G-IN) which has a LCD to display the amount drawn from the components attached to it and rated voltage it draws from the wall socket.

I dont get any spikes and if I get, my UPS controls it efficiently other than a lightning strike where nothing can be done.

Even a govt electrical transformer will not be able to bear a lightning strike.

PS: Before I used APC 600VA UPS which is still working efficiently and not once did my components get fried due to voltage spikes.
Mostly Asus Motherboards have software in the bios itself to shutdown the PC in case of Voltage Spikes or irregularities.

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## quicky008 (Dec 4, 2016)

I was talking about situations when the mains voltage from the AC power supply increases to 250-260V,afaik voltages in excess of 250V is not considered safe for electronic devices esp. delicate equipments like PCs and a good ups is supposed to step it down to safe operating levels,which should be ideally between 200-230 V.I have an older BE650Y-IN apc ups which does exactly that....when the voltage drops below 200V it boosts it to ~220V and when it goes above 250V it steps it down to 210v or thereabouts.I live in a rural area where voltages tend to stay above 250 V(250-260V) or below 200V most of the time-therefore its imperative that the ups should have the capability to boost or trim the voltage to safe levels as required-otherwise i'm afraid my equipments may get damaged in the long run.

However much to my dismay my new ups does not intervene or attempt to regulate the voltage when it rises to unsafe levels(~260V),leading me to wonder whether it really does have an AVR or not and even if it does,whether its functioning the way its supposed to or not.The documentation provided with the ups is very sparse and although it says it features an AVR it doesn't describe how exactly does it work and when exactly does it attempt to regulate the voltage to safe levels(if at all).So i'm having serious doubts about the reliability of this UPS.And FYI i checked the voltage readings using a digital multimeter.

And i think most consumer level upses today do have the capability to protect equipments from lightning strikes(atleast in theory) as they purportedly have something called Surge protection which is supposed to take care of such issues.Although i've never had an opportunity to this out,i hope it really does work.

(p.s. can you mention the model no. of the 600VA ups you had been using earlier?)


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## kARTechnology (Dec 5, 2016)

265v...max safe for any equipment...
afai have tested Chinese LED ceiling lights(~100 lights 12W) get damaged beyond 265v. those electronic ballast(or ac-dc converter in specific) get damaged and then so the light starts to flicker or die/dim.
and 3 phase big 11ton central ac's cant handle more than 270....u get burning smell from blowers and then fire...


I am not using stabilizer and directly running off UPS's(pure sine wave)
and in rural area where the voltage is >280 I use a buck-stabilizer from a local power-line brand from hyderabad as input to the inverter and then the devices are connected to inverter...works very, very well.

many ups's tell they have AVR(APC BR-600CI-IN for example ) but they don't have and simply cut off/go to battery mode)
my old numeric 600va bucked to 240v when input is 300v. winner.

how can lightning strike affect devices?
my local fiber broadband lost all its PoP(point of presence) switches during a lighting....
many lost their routers and NIC's as well...
idk it didn't affect my router and the PoP box(which holds the fiber-> lan switch)
I think in the above case those APC 1000va of 7-8k price having lan cable surge protection would have helped.


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## quicky008 (Dec 5, 2016)

kARTechnology said:


> 265v...max safe for any equipment...
> 
> I am not using stabilizer and directly running off UPS's(pure sine wave)
> and in rural area where the voltage is >280 I use a buck-stabilizer from a local power-line brand from hyderabad as input to the inverter and then the devices are connected to inverter...works very, very well.
> ...



Thanks for your inputs.I think the tolerance level of chinese lights is a bit higher than that of delicate electronic equipments such as computers for which,as a rule of thumb,the most suitable voltage levels is regarded as 10-15% above or below 220V-anything that exceeds those limits is treated as harmful.

I've also read some disquieting reports that certain upses supposedly don't have any built in AVR even though they are advertised as having this feature-i didn't know that even a company of international repute like APC engages in such malpractices-don't you think it makes them liable to be prosecuted in a court of law for deceiving their customers like this?

BTW how did you discover that BR-600CIN doesn't have AVR?Do you know whether its newer sibling the bx 600C-in lacks this feature as well or not?Is there any test to determine whether an ups does or doesn't have an AVR?

My older APC BE650Y-in was a great ups and had the capability to regulate voltage very well-i seldom faced any issues with it.However i don't get the same kind of confidence while using this newer BX600C-in ups which appears to be of a much lower quality and is very likely to be unreliable.It feels really disappointing when a company like APC churns out such low grade products which are as good as useless and don't serve the purpose for which they're intended to be used!I feel like i've been had


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## kARTechnology (Dec 5, 2016)

quicky008 said:


> Thanks for your inputs.I think the tolerance level of chinese lights is a bit higher than that of delicate electronic equipments such as computers for which,as a rule of thumb,the most suitable voltage levels is regarded as 10-15% above or below 220V-anything that exceeds those limits is treated as harmful.
> 
> I've also read some disquieting reports that certain upses supposedly don't have any built in AVR even though they are advertised as having this feature-i didn't know that even a company of international repute like APC engages in such malpractices-don't you think it makes them liable to be prosecuted in a court of law for deceiving their customers like this?
> 
> ...



why does APC need to have a "Sensitivity Setting" for input voltage window...depending on this setting it will switch to battery  mode as per doc...
In rural area for CCTV we have used a APC BR600-CI-IN(not exactly remember the model) and the battery died in few months of operation. the reason is there is no avr and it used to run on battery all night, I saw this as i heard the unit beeping during night time(though the camera ) and the cctv shut down after it ran out of charge.
So i moved to numeric 600 va and even tested with multi-meter...and hence it proved. APC has NO AVR even for its premium 7-8k 1000VA ups  with display,. why bother with sensitivity setting when u have an AVR? It's because it doesn't have one, false marketing.

So later i moved to stabilizer(4kva AC stabilizer 200-290v)->Inverter(1000va)-> CCTV & other load which is really working very well.

APC...I brought their power strip for 1.5k I think and shocked it see that it was a made in India(all the products i have used, which are made in India, are of crap quality. only one manufacturer(sorry a ECE engineer) designed a inverter and it is better than any other inverter in the market, Yes, but It is the bitter truth), ok but why use cheap quality components.
*advertised as 2.1A* USB current but *getting barely 700-800ma*...suitable for charging dumb phones

We people choose APC for its foreign + great quality...but it didn't hold.
many other brands also are in the same boat.

We use Corsair, Antec, Cooler Master, Seasonic...all imported...
before telling to use made in India products. they must beat the quality of the rest imo, else I do not buy them.
Zebronics(chineese rebranded is not Indian) 400W *Rs -500-Rs700*
Corsair cx430 - *Rs 3000* - buy this. Reliable. and it proved too.
I do not buy products especially made for India & other countries instead of world wide...like antec few psu's were not there in US.


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## bssunilreddy (Dec 6, 2016)

Yes, low end PSUs like 430w, 450w made for Asia Pacific regions are very low quality. They can barely withstand more voltage before getting fried.

Seasonic PSUs like 430w, 520w, 620w are superb in their quality. They are made not for one specific region and comes with universal power cables. Such power supplies are made with top quality components.

Even Corsair VS series PSUs are for asian markets only and prone to damage to itself and other components as well.

But from Corsair CX series onwards its somewhat good.

Similarly Antec also has same kind of PSUs.

Don't ever go with low end Cooler Master PSUs.


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## quicky008 (Dec 6, 2016)

bssunilreddy said:


> Yes, low end PSUs like 430w, 450w made for Asia Pacific regions are very low quality. They can barely withstand more voltage before getting fried.
> 
> Seasonic PSUs like 430w, 520w, 620w are superb in their quality. They are made not for one specific region and comes with universal power cables. Such power supplies are made with top quality components.
> 
> ...



this worries me coz i have a VS450 in my system currently


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## kARTechnology (Dec 6, 2016)

quicky008 said:


> this worries me coz i have a VS450 in my system currently



I have around 6 CX430 PSU's...still working...
though the oldest one gave a spark, one day on powering it up but still working...
one was used in a very heavy dusty condition and the result is the PSU fan now makes creaking noise when PSU is vertical(fan sideways)
all my HDD's have stopped getting bad...before when using zebronics frequently the C drive used to corrupt and resulted in boot failure.


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## tekiagadi (Dec 19, 2016)

According to me, The Range of 110-120 volts is safe for the Personal Computer.


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## quicky008 (Dec 23, 2016)

^ in india,the normal voltage of ac mains line is 230V,therefore your suggestion is not applicable to indian users.


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