Is 500V UPS enough?

[Knight]

Hi All,
My config is AMD 2600+ (barton 512K), ASUS A7N8X-E Deluxe Mobo, 500watts SMPS, 512 MB DDR RAM, ATI Radeon 9600XT DisplayCard, Samsung Samtron 55V (15 inches), Logitech keyboard and mouse.

At present, i have 500V UPS(Brand - SBS). Is this ok?

Or do I have to replace it with a 800V UPS?

Please clarify.

[funkymonkey]

ok enough to save your work and shut your PC down.

[Prashray]

500V is enough.

[Knight]

Hi all,
thankx for the reply.
my another worry is will it enought to handle 500wSMPS, 15 inche monitor and ATI Readion 9600XT?

one of my friedn todl tha ATI radeon 9600 based cards need mor power supplyl. he asked me to go for 800V.

does it make sense?

[icecoolz]

thats not true,

I have a 17inch monitor and a 500W SMPS with a Geforce 6800 mate and I dont have any issues whatsoever.....

[aadipa]

more VA means more backup....
thats all

[amitsaudy]

500 VA will do the job.
But your backup time will be very short but long enough to shutdown
ur system safely.
But cant say how reliable your ups is 'SBS'?..must be some local brand.
Always buy APC.

[pradeep_chauhan]

at 500V you will burn the PC the voltage should be 230V (Please correct me if i am wrong????)

[icecoolz]

Pradeep....thats not referring to the voltage its VA as in Volt Amps so its correct. Ofcourse the output for India is 230 volts mate so dont worry abt it.

[Astrix]

How much approx is APC 500VA?

[theraven]

hmmmm well since u already have it .. go with it till i dies down
after that go in for an 800va

my apc 500 va died down on me i got rid of it .... next buy is a 1kva for me !!

so think abt the amt of backup time i need ...
at that load .... i think ur 500 va will give u 7-10 minutes of backup time MAX ... so that should be enuff for u
the main thing is gettin protected by voltage surges .... and shuting down safely .... which 5 min should cover for most of us !!!

[AlienTech]

The VA rating has nothing to do with backup time. VA is the volts * Amps that the unit takes in or you pay the electricity company. Usually the unit has an efficiency rate of 60%. Since it has to convert 240Volts AC down to 12V DC to charge the battery. Then it has to convert the 12V DC into 240V AC. IF the UPS uses SMPS power supply you get a higher conversion rate. So you have to take the UPS rating of 500VA and convert it to Watts which is the output rating. So 500VA becomes like 300W atts. (Volts * amps = Watts, as you can see Volt-Amps is the same as Watts but one is used for input while the other is used for out put here.)

The backup time depends on the battery size. The drain also affects it since there are problems with the battery draining too fast shorting the backup time a lot. IE a battery can last longer if you drain it at a less rate. So a 7AH (amp hour) battery can last 10 minutes with a 300 watt load on it, while the same battery can last 30 minutes with a 150W load on it. Even though the load is only half at 150Watts than at 300 Watts, you get triple the time and not double. This is due to the battery characteristics. So putting 2, 7AH batteries in parallel would give you 30 minutes and not 20 (since each battery would give you only 10 minutes, 2 must give you 20, instead it gives you 30).

As you can see, a number is just a number... If you do not know what they mean, it really can mean almost anything. A cheap 800VA might not be all that much better than a well quality made 500VA UPS.
Also a well made UPS will handle flutter in the power lines and feedbacks caused by people turning on motors and fans. These send HUGE milli second spikes down the power lines and can cause lockups.

[pradeep_chauhan]

no no the funda behind VA and watts is a bit more complex A new variable called power factor is also involved so 500 VA is the rating for a "Pure" load ie having a power factor as 1 this is true only for a resistive load like say a room heater or an iron. Now all other eqpment have a lag or lead power factor lag = inductive loads and lead = capacitive loads. genrally the power factor is taken as 0.8 so the load in watts is now given as V*I*Pf so we have 500VA*0.8=400w this is the load the ups can supply at a max. Also this is the unit by which power coy charge customers not VA.

The other thing is that ups do not use smps power supply, the power supply is in the pc , monitor and say printer all of these are smps. The invertor or ups use tecniques like pwm (pulse width modulation) or high freq modulation to convert the low 12V DC to 220-240V AC .The conversion factor depends to a great extent on the tecnique used and also newer tecniques like use of torridal transformers ets raise the conversion efficecy to good about 80% Also the conversion efficency increases with higher battery voltages used (conductor loss reduces) so new designs use 24 V (2 x 12V btty) to achive this. The backup time as rightly said depends on batt AH (Ampear hour)capacity of the backup batty used. The other thing that needs to be addressed is the switch over time and spke protection in the O/P supply.
The design of UPS is a vast field and the best way to avoid all this jargon is to buy a good 500VA UPS from say TVSE or APC and enjoy. Personaly i use a APC and TVSE ups to power my 4 PC. two each on one ups one has a 17 inch monitor other are regular 15inch I get a backup time of about 5-8 mins.

[pimpom]

Hello AlienTech, I was about to post something similar to yours but
you beat me to it. I've often seen ppl equating VA rating to backup
time. Your explanation is technically correct but I'd like to add some
qualifying statements.

In practice, there could be some truth in saying that higher VA =
longer backup time in the sense that an 800VA UPS meant to provide a 10-minute backup will have a battery with a higher Ampere-hour (Ah) rating than a 500VA unit with the same 10-minute backup time.
Therefore, with the same load, the 800VA unit will provide longer backup than the 500VA model.

But I'm not really arguing with the points you made. I think most
people usually mean that more VA means longer backup, period. In that sense, they're wrong of course. If a choice is available, it makes more sense to buy a lower VA UPS with a larger battery, or an external battery model.

Personally I use a 600VA UPS with a 70 Ah external battery. And I often install heavy-duty UPS'es with upto 150 Ah batteries for people who have to keep working even when there's an extended power outage.

[theraven]

well since u guys are talkin abt my post
ill just make it clear

Originally Posted by pimpom

In practice, there could be some truth in saying that higher VA =
longer backup time in the sense that an 800VA UPS meant to provide a 10-minute backup will have a battery with a higher Ampere-hour (Ah) rating than a 500VA unit with the same 10-minute backup time.
Therefore, with the same load, the 800VA unit will provide longer backup than the 500VA model

that was my only point
going into technical details wasnt required so i simply put it in lay mans terms ... cuz the above quote holds true for sure
Ah ratings of batteries are set to match the VA ratings
anyways ... really nice description m8's
i personally hate going into ratings in such details

[AlienTech]

Originally Posted by pradeep_chauhan

no no the funda behind VA and watts is a bit more complex A new variable called power factor is also involved so 500 VA is the rating for a "Pure" load ie having a power factor as 1 this is true only for a resistive load like say a room heater or an iron. Now all other eqpment have a lag or lead power factor lag = inductive loads and lead = capacitive loads. genrally the power factor is taken as 0.8 so the load in watts is now given as V*I*Pf so we have 500VA*0.8=400w this is the load the ups can supply at a max. Also this is the unit by which power coy charge customers not VA.

The other thing is that ups do not use smps power supply, the power supply is in the pc , monitor and say printer all of these are smps. The invertor or ups use tecniques like pwm (pulse width modulation) or high freq modulation to convert the low 12V DC to 220-240V AC .The conversion factor depends to a great extent on the tecnique used and also newer tecniques like use of torridal transformers ets raise the conversion efficecy to good about 80% Also the conversion efficency increases with higher battery voltages used (conductor loss reduces) so new designs use 24 V (2 x 12V btty) to achive this. The backup time as rightly said depends on batt AH (Ampear hour)capacity of the backup batty used. The other thing that needs to be addressed is the switch over time and spke protection in the O/P supply.

The design of UPS is a vast field and the best way to avoid all this jargon is to buy a good 500VA UPS from say TVSE or APC and enjoy. Personaly i use a APC and TVSE ups to power my 4 PC. two each on one ups one has a 17 inch monitor other are regular 15inch I get a backup time of about 5-8 mins.

good post..

But I have a UPS that uses SMPS, made by megatech. IE it does not have a transformer to convert 240V to 12V.

Also the power factor in countries are different.. Some countries will lead or lag the voltage. Which is why some equipmenet like fans and motors will work well in one country but not another even if the voltage and frequency are the same. It is also why you get a higher or lower bill for a particular device even if the price for electricity is the same.

I hooked up a 120AH one to the megatech maxium 500 I get hmmm dont know since I havent run it long enough except for a few hours. The unit can not charge the battery properly if the battery gets discharged but since power failure is only for 1 hours in a 100 it works out.




-----
To those who don't know about AC/DC voltage-currents.. In AC the voltage goes from 0V to 240Volts. But the current which is the power or omph used to drive your device does not follow the voltage, It can lag or lead the voltage like the crankshaft in a car engine. Both voltage and current have to be multiplied to get the omph factor like at the center of the crankshaft there is no power to turn anything.

This means the maximum omph you get might not be at 240V but at 120V when the current is at max. You can kind of fix this by using a capacitor in series to store the current for the times its missing.

[senthilrek]

800V UPS would be better

[pradeep_chauhan]

AlienTech
The use of SMPS for converting 240V to 12 or more precicely 15.5V for charging the btty is very common, What i was refering to is the up conversion from 12 to 240v. Also The comment that "Also the power factor in countries are different.. Some countries will lead or lag the voltage." is not correct . Every one wants to keep the Power Factor to 1 This is why there are massive capacitor banks at power distribution stations that are switched in / out to correct the lag No one or no company will want to vary the power factor as it causes the machines to loose there opimal performance. In USA and europe every home / factory has to assure that the power factor is not dropped due to their load and each place has a power correction equipment connected to the mains inlet point. Thus power factor is a "drawback" that one has to live and fight. In india also if you see the good quality tubelight fixtures made by say bajaj or CG you will find a 1or 1.2 uf 400v capacitor connected. This is to correct the lag created by the inductive load offered by the choke used in the tube lights.
In case of UPS if you open one and see you will see a 0.47 to 0.68 uf 400v capacitor connected at the output (towards the PC) to overcome the lag created by the filter choke or the pc load.
A long time (1990 when i was doing my BE) back i too made a project that auto corrected power factor for the industry Tha time it was a hot topic and something new but over the times the devekopment of new semiconductor devices the fabrication of this unit has become child's play.

[Sinnet]

m8 500 VA is ENOUGH
i have a AMD Athlon 2800+
i run 2 hdd's , both 160 GB SATA and 1 CDRW and
1 DVD RW and a radeon 9600 and a 17" monitor on my
500 VA APC Back-UPS
and it runs fine and gives me decent backup time
so no worries and u dont need to go in for a 800 VA UPS
enjoy

PS : my system has 4x 80 mm cooling fans and the system still runs
stable

[paid]

We hardly get 30-45 minute backup on UPS, for longer backup UPS-cum-Invertor's now available in market with backup of 4-5 hours.
Someone using UPS-cum-Invertor plz. write your review with brand name and price......Thanks

[pradeep_chauhan]

Please do not use an inverter in place of an UPS as you will end up damaging your pc sooner or later. The technology used in an inverter is the same as in a UPS but for a few small but important things. Firstly the changeover from mains to inverter is through a mechanical relay(remember the familier click) this changeover method introduces a delay that is not exceptable for computers and will cause hdd failure, PC reset or burnouts. Secondly the waveform in an inverter is highly unfiltered with lots of harmonics these are very dangerous for sensitive eqpmt . Lastly the inverter voltage is alwase load dependent starting at 260V at no load and dropping down as the load increases this too is very harmful. Thus i would recommend never to use an inverter as a UOS substitute they are two diffrent equpment for two very diffrent roles.

[grinning_devil]

...still wanna connect inverter to PC???
Why not go ahead and connect inverter to UPS nd frm UPS to PC???
Never tried that....but will be possible i guess....

...will try it as sooooon as warranty is over....!!

[TheGuru]

500 VA is sufficient for around 10-min backup atleast (assuming you are not playing 'heavy' games during this time).

Though you have a 500-watt SMPS, your system will hardly be pulling 200-250 Watts for an ordinary system - upto 450 Watts for a system with current-generation high-end graphics card, sound card, multiple optical drives and other peripherals.

What really matters is the sustained load on the UPS. As long as you are not playing games or stressing your hardware, you are good-to-go. But, if you don't want to exit your game immediately (hoping that the power-cut is only for 5-10 min), you better get yourself a 800 VA UPS

[AlienTech]

Originally Posted by grinning_devil

...still wanna connect inverter to PC???
Why not go ahead and connect inverter to UPS nd frm UPS to PC???
Never tried that....but will be possible i guess....

...will try it as sooooon as warranty is over....!!

I have connected a UPS to UPS because one of my UPS's works upto 150 volts but it does not work too good when there is line feedback like someone switches off a motor that send these high voltage spikes down the line and crashes the computer.. But my other UPS only works upto 190V but its very good (well was very good until one of the chips blew and I cant find any info on the chip.. RFP40N01).. Here the voltage sometimes drops to 160V in the evenings, happens every day where my wife lives.. So I think the inverter to UPS would also work.. But remember, each of them looses 20-30% of the electricity.. So you end up only getting like 50% of the power you pay for. A UPS would not work very well for something like a FAN because its an inductive circuit rather than a resistive circuit like a PC.. Although they will work, the efficiency would be rather low.. IE you only get like 60-70% of the electricity you pay for. Not sure how they fix it so it works well for a PC and a FAN.. Like the UPS/Inverter combo..

[AlienTech]

Also remember, If you are using your UPS every day, In 1 year you only get half the time, The battery when new can be recharged around 200 full cycles before it looses 1/2 the capacity... The next year it becomes 33% of the time.. and on.. So you need to change the battery every year or so if you use it every day. So shutting your system down as soon as the power goes discharges the battery less so it lasts longer.. I went through 5 sets o fbattery in 3 years because I needed the system to be up during the 30 min power failure every day. So now I got a 120AH battery hooked to it. Costs enough for 10 of the small ones, but the warrenty is 5 years and I think the battery would last for 10 years. I also get like many hours from it but only tried upto like 90 minutes on it.. So not discharging the battery is important if you need to have the full 15 minutes when needed...

[pimpom]

Originally Posted by AlienTech

one of the chips blew and I cant find any info on the chip.. RFP40N01)..

Do you mean an RFP40N10 ? That's a 40Amp, 100V MOSFET. If you can't get a replacement, I can probably find an equivalent for you among the standard industrial types. But not right now - We're rennovating the house and everything's a mess and I don't know where I've placed my data books

[grinning_devil]

nice posting Alien.....!!

my battery is ALMOST DEAD on UPS i guess...
damn just 3/4 mins of backup...
as well as automaticaly goping to battery mode,with NO fluctuations,
NO spikes..!!

so nyone have a nice complete rate list of gud quality UPS's???

[AlienTech]

Originally Posted by pimpom

Do you mean an RFP40N10 ?

Lol yea thats it.. I was reading it upside down

$1.60 each...
RFP40N10 40A, 100V, 0.040 Ohm, N-Channel Power MOSFETs
http://www.fairchildsemi.com/pf/RF/RFP40N10.html

Still got to see if I can get this in india.. Seems not many uses for this one.

The more common ones I see are the IRFZ44N or PHP44N for rs 50 Unit Price ( USD ) : $ 0.554 or so... which is 55V 50amps..


http://www.semiconductors.philips.co...06LT#datasheet

[AlienTech]

Originally Posted by grinning_devil

so nyone have a nice complete rate list of gud quality UPS's???

This would be very hard to do. You would most likely have to talk to a repair shop that has seen many of them. The components used makes a huge difference in how well they work. Like my megatec would switch off by itself and on when the power came on when there was no load on the system. It uses a rs 10 transistor to do this.. (As I found out when I blew it up while trying to hook up a fan to the unit as it got very hot because there were no vents on the unit at all.)... Now this auto switch off is a very good thing since it shuts the UPS off when your computer is not on. But you also dont want it to auto switch itself off when you turn off the monitor to increase backup time.. I tried to tell the guy who I bought one of the UPS from that there was a problem with the UPS switching itself off after 2 minutes IF I had the monitor turned off. But the computer was still on. After a few weeks I gave up on it. He could nto understand it. Kept telling me well does the computer and monitor stay on for 15 mins? I go yea.. Well then he says so whats the problem... Back to square one again.

With the megatec I can just have the modem on and it wont shut off. While if there is no load at all, It will shut off after a minute.

I think most units made by large manufacturers would have such features.

The markets a mess these days. They are selling stuff they cant even begin to understand.

[AlienTech]

I wonder how good wipro is... The 500AV is like 2800 and 600 VA is 1000 more for the low cost entry ones... specs look good..

http://www.wepindia.com/news/PRESSCORNER1.ASP

WeP Peripherals (new name for Wipro ePeripherals Ltd.), the leading IT peripherals solutions and services enterprise has launched eMerge 550G UPS, a unique product, which protects the PC from all Generator Waveforms and its related problems. This new UPS from WeP has been extensively tested with all key generators and in key geographies such as Lucknow where the generator usage is extensive.

WeP Peripherals (new name of Wipro ePeripherals Ltd.), the leading IT peripherals solutions and services enterprise has launched eMerge 600 VA, 360W Line Interactive UPS, which is specifically targetted towards the Home Office and SME segments. The UPS, which is being manufactured at WeP’s Hyderabad unit is capable of handling variations of voltage from 160V to 300V. WeP had commenced manufacturing of UPS at the Hyderabad unit last year and the company has made significant investments in terms of manpower and material resources in this direction.

This 600 VA, priced at Rs. 5,100 + taxes comes with a unique warranty proposition of two years on the product and battery. The customers also have the unique benefit of the 30 Day Money Back Offer.

Wipro ePeripherals Ltd. (WeP), the leading IT peripherals solutions and services enterprise has launched eMerge UPS 1000 and UPS 1000e, which are specifically targetted towards Small Workgroup protection. Both the products are line interactive 1kVA UPS’s. WeP has also commenced manufacturing of UPS at the Hyderabad unit. The company has made significant investments in terms of manpower and material resources in this direction.

The eMerge UPS 1000 provides 20 minutes backup with two PCs whereas the eMerge UPS 1000e has a provision to extend the backup time by adding additional eMerge 1000e backup extender.

Apart from the new products, WeP is the only UPS vendor offering choices in 500VA category, which is the largest in UPS segments. eMerge 500 at Rs.3995/- to customer as economical and entry level option and eMerge 525 Hi-Range which comes with widest input voltage range of 140 to 300V as the premium option for ultimate PC protection.