# compatibility of Inverter with UPS



## Tech123 (May 18, 2012)

Details :

Now my sukam inverter has two modes UPS mode and W-UPS Mode ( Wide UPS mode) 

UPS mode output range - 185V ~270V ( as one can see very narrow operating voltage) 
W-UPS mode Output range - 115V ~295V ( Wide operating voltage- Good if power in your area, like my area, fluctuates ) 

UPS Mode:
If I keep inverter in UPS mode, PC will not reboot when inverter goes into back up mode.
but if I keep inverter in W- UPS mode - Pc reboots in back up mode.

So naturally I will want to keep inverter in UPS mode so that PC does not reboot during back up right?

But the disadvantage of UPS mode is that as soon as supply voltage falls below 185 , it goes into back up mode , so in spite of their being power , but low voltage , inverter will be in back up mode and drain the battery. During this time there will be no charging , so battery will drain soon.

So voltage dropping below 185 is like power failure for inverter in this mode, hence battery is not getting sufficiently charged and I will get less back up, although PC does not reboot in this mode.

W-UPS mode- 
Battery charges fabulously as in this mode the Range is wide 115~295, so even if voltage drops below 185 or 140, inverter is still on mains and does not go into back up mode , battery gets charged well, but when inverter is in this mode and there is power failure , then PC will reboot. As there is slight delay in back up in this mode, ( although I cannot understand why manufactures cannot overcome this disadvantage of this Mode) 

So what mode do I keep the Inverter in especially when the supply voltage , most of the time is falling below 185V in my region, causing inverter to go into back up when in UPS mode?

if I keep in UPS mode battery Drains and if I keep in W-UPS mode, PC will reboot in case there is a power failure in this mode. I cannot control the Supply voltage to be over 185V all the time can I? so that I can get the Best of Both Modes.

My Intention:

Connect a Small Computer UPS (online interactive UPS), the ones that are small and come with every computer, the ones that provide 15 to 20 min backup.( Cost Rs.2000 - 3000 )

These provide instant switch over, no rebooting takes place.

So Power supply -> Inverter -> Small Computer UPS -> PC

I intend to connect this computer UPS to the output of my inverter, and keep my inverter in w- Ups mode, 
so now in w-UPS mode, even if the voltage falls below 185 or 140 my inverter will not go into back up mode, and when there is power failure, the small computer UPS will instantly switch over to back up and prevent my PC from Rebooting,a few seconds later , my inverter will start supplying power to my Small computer UPS and my small computer UPS will dis- engage from Battery mode. So no rebooting even in w-UPS mode.

So for the small Computer UPS, it will be like power has come back on.

so I will have the best of both the Mode, No Rebooting and No going into backup mode when low voltage comes, so good charging.

The only problem; When output of Inverter is connected to Small Computer UPS there is this tick tick noise from the small UPS.

Some say small UPS voltage sensitivity needs to be adjusted, because this clicking sound is from Relay of small UPS.

I really don't know how to solve this.

Inverter is pure sine wave , the out put of inverter is like the output of supply voltage( According to Manufacturer) ,Yet when the Small UPS is connected Directly to the supply there is no Tick tick noise but when connected to inverter there is this Tick tick noise , so what do you people think?

Why is the small UPS behaving differently with inverter? Inverter power = Supply power, as both are pure sine wave.Or is there a defect in the inverter ,maybe it is not able to produce pure sine wave so Small UPS is having difficulty . 

My Small UPS model : Microtek HGE600AZ
Inverter Model: Sukam Shiny Series 850VA( Pure Sine wave )
Please suggest, thank you.

Such a huge forum and not a single reply ?? are there no knowledgeable people here , sorry .


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## d6bmg (May 18, 2012)

Always use W-UPS mode.
Running Inverter in W-UPS mode means when Input voltage is between 115V-295V, connected peripherals will run from main power, and if it goes bellow 115V, backup power will be initiated.
There is no link with battery charging and two modes of any inverter.
Battery charging is generally controlled by another feature called 'charging voltage'. You can see that switch at the back or front panel of inverter (position will depend upon the model)
P.S. your 850VA inverter is more than enough.


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## whitestar_999 (May 18, 2012)

there is a reason why w-ups mode is not recommended for running pc by directly connecting it to inverter without ups(my inverter has ups & inverter/w-ups mode) & i have tried both with 600VA intex ups.PC's power supply is very sensitive compared to normal electrical appliances so wide range/low voltage fluctuations can easily cause damage.in inverter/w-ups mode sometimes due to very low voltage my intex ups switch to backup mode even though inverter is still supplying mains power.the tick tick voice in your ups may be due to fast voltage fluctuations in mains which sometimes also happen in my intex ups too since inverter also try to stabilize output meaning ups input also changes frequently.when ups is directly connected to mains then fluctuations are handled by ups mechanism only which is more efficient in handling such situation & hence the no tick sound.remember inverter is designed to run as alternative power to home electrical appliances so it handles load fluctuations differently from a ups.


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## Tech123 (May 20, 2012)

d6bmg said:


> Always use W-UPS mode.
> Running Inverter in W-UPS mode means when Input voltage is between 115V-295V, connected peripherals will run from main power, and if it goes bellow 115V, backup power will be initiated.
> There is no link with battery charging and two modes of any inverter.
> Battery charging is generally controlled by another feature called 'charging voltage'. You can see that switch at the back or front panel of inverter (position will depend upon the model)
> P.S. your 850VA inverter is more than enough.




Please note in UPS mode if voltage falls below 185 then there will be no charging, as the inverter will be in  back up mode, so when inverter is in back up mode , then charging does not happen.

hence if we have constant low voltage then inverter will always be in back up mode so how can charging take place?

hence we have to use w-ups mode which has a wider operating voltage, it is apparent that  you haven't used such a inverter , it may be difficuilt for you to understand this issue. Now days these inverters are smart. please read my original post carefully then you will understand the issue  appreciate your efforts to provide solution , thank you.



whitestar_999 said:


> there is a reason why w-ups mode is not recommended for running pc by directly connecting it to inverter without ups(my inverter has ups & inverter/w-ups mode) & i have tried both with 600VA intex ups.PC's power supply is very sensitive compared to normal electrical appliances so wide range/low voltage fluctuations can easily cause damage.in inverter/w-ups mode sometimes due to very low voltage my intex ups switch to backup mode even though inverter is still supplying mains power.the tick tick voice in your ups may be due to fast voltage fluctuations in mains which sometimes also happen in my intex ups too since inverter also try to stabilize output meaning ups input also changes frequently.when ups is directly connected to mains then fluctuations are handled by ups mechanism only which is more efficient in handling such situation & hence the no tick sound.remember inverter is designed to run as alternative power to home electrical appliances so it handles load fluctuations differently from a ups.



@ white star:

hi 
it seems that you have understood the issue.
You are correct , as both inverter and computer UPS are trying to provide back up hence this noise oculd happen.

I Plan to get the relay of the small UPS checked/ repaired , I think the problem is with the relay of the small ups



d6bmg said:


> Always use W-UPS mode.
> Running Inverter in W-UPS mode means when Input voltage is between 115V-295V, connected peripherals will run from main power, and if it goes bellow 115V, backup power will be initiated.
> There is no link with battery charging and two modes of any inverter.
> Battery charging is generally controlled by another feature called 'charging voltage'. You can see that switch at the back or front panel of inverter (position will depend upon the model)
> P.S. your 850VA inverter is more than enough.



Cannot use W-UPS Mode as PC will Reboot in this mode when there is a power failure, in this mode there is a small lag before back up is restored.


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## arayman (Jun 22, 2012)

Tech123 said:


> Details :
> 
> Now my sukam inverter has two modes UPS mode and W-UPS Mode ( Wide UPS mode)
> 
> ...




When I read your post it was like I am reading my own problem. I am facing exactly same issue, which is very frustrating. I have inverter "Su-kam" it is falcon series. Its an old model therefore in it they named the modes like 'inverter mode' and 'Ups mode' there is no W-ups, I suppose they changed inverter mode to w-ups in new models.  Beside the problem stated by you, I have an additional issue which has to be resolved yet. As you wrote even my inverter starts back up when kept in ups mode. And when I try to keep in inverter mode my pc reboots. I already had UPS connected to my pc but my ups could not avoid re-boot of my pc as there is a fraction of second delay till the UPS takes over. Can say its some mysterious issue which I have discussed with lot of technicians. All are clueless.  

The only theory they could evaluate is that when there is power outage there is slight dip in electical volts which confuses the UPS for 1-2 milliseconds before it starts, by the time it provides back up the loss has been done and my pc re-boots. (I also tried other ups but no use). But when I am on UPS mode of inverter my pc never reboots the reason is that the dip in power at time of power outage is well accessed by inverter than small ups and inverter change over time (in ups mode) I suppose may be a little faster than computer UPS. I hope now you can imagine that how important is inverter (in UPS mode) for me. 

I spoke to sukam engineer if he could provide some solution so that the inverter keeps charging the battery in UPS mode. He said they can do some setting for letting it charge the battery below the 185 volts BUT I thought if I get it done my pc and other devices will be at risk when the voltage is below the required range, as they are working directly with minimum power regulation done by inverter. 

Thus after thorough assessment of the situation I thought if the inverter is connected to small power corrector, automatic or manual (which we use in Refrigerators, once used for television manual types etc.) the power output will remains constant as it won't let it dip below 190 volts and the inverter will keep charging the batteries in UPS mode too, protecting the inverter from low and high voltage as well as my pc and would solve my purpose. BUT I am a bit skeptical about this idea. I need to discuss with a techguru if it would be successful. I read somewhere that stabilizers should be avoided with inverters. Still no harm in inquiring. If this set up works it would be like this Main power>Power corrector>Inverter (in UPS mode)>PC. 

Now regarding your problem of tick tick noise in UPS. Well its quite normal as the relays are regulating the voltage may be there is lot fluctuation happening on your area hot lines. Had your inverter been Non sinewave (square wave) it would have damaged your pc at first place and moreover square wave create buzzing sounds in fans, pc speaker etc. So rest assured your inverter is normal along with your ups. The nuisance is being created by your main power supply. Earlier when you were using inverter in ups mode you were ignorant about the power regulation/corrections being done by your inverter but when you connected ups it sitting near to you thus you got attentive to it. 

By the way, in my case, as I cannot use pc ups so I have kept a dedicated inverter line for my pc and as soon as I finish my work I change the mode to inverter mode, and during the night I always keep it on inverter (W-ups) mode so that the batteries don't get deeply discharged or exhausted.


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## vickramperumal (Jun 30, 2012)

My inverter is a Luminous (Pure sine Wave) 875VA and UPS is Numeric make and its battery has worn out and has literally no backup. The backup from my UPS lasts only for 10 seconds. Instead of purchasing a new UPS I thought I will purchase an inverter and connect my PC through UPS, the same plan as "Power supply -> Inverter -> Small Computer UPS -> PC”. The advantage I thought is that UPS can give only 20 mins of backup, while inverter can give at least 8 hours of back up. As my UPS has 10 seconds back up it should be sufficient to prevent reboot of computer during switch over from mains to inverter. My modus operandi was that Inverter will provide prolonged back up and UPS will give more refined current to the delicate computer. But unfortunately this blue print flopped. My computer shuts down and UPS refuses to switch on emitting low battery warning beep wile switching from mains to inverter power. The load is not an issue. I had tried switching off all loads then switching only my UPS. The result was the same. As a next move I planned to buy a new UPS. I saw many UPS brands claiming "compatible with inverter/generator” (claimed by Microtek UPS), some claim “compatible with generator” (claimed by Luminous UPS) . I was almost about to purchase a Luminous UPS but luckily stumbled upon this post. 
My question now is 
Will using an UPS "compatible with inverter/generator" solve this problem? 
Is UPS claiming "compatible with generator" also compatible with Inverter
For the records my father is using an APC UPS with SU-KAM inverter and he claims he has no such issues. He even chats with me during power cuts.  
Please help me to take a decision.


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## arayman (Jun 30, 2012)

vickramperumal said:


> My inverter is a Luminous (Pure sine Wave) 875VA and UPS is Numeric make and its battery has worn out and has literally no backup. The backup from my UPS lasts only for 10 seconds. Instead of purchasing a new UPS I thought I will purchase an inverter and connect my PC through UPS, the same plan as "Power supply -> Inverter -> Small Computer UPS -> PC”. The advantage I thought is that UPS can give only 20 mins of backup, while inverter can give at least 8 hours of back up. As my UPS has 10 seconds back up it should be sufficient to prevent reboot of computer during switch over from mains to inverter. My modus operandi was that Inverter will provide prolonged back up and UPS will give more refined current to the delicate computer. But unfortunately this blue print flopped. My computer shuts down and UPS refuses to switch on emitting low battery warning beep wile switching from mains to inverter power. The load is not an issue. I had tried switching off all loads then switching only my UPS. The result was the same. As a next move I planned to buy a new UPS. I saw many UPS brands claiming "compatible with inverter/generator” (claimed by Microtek UPS), some claim “compatible with generator” (claimed by Luminous UPS) . I was almost about to purchase a Luminous UPS but luckily stumbled upon this post.
> My question now is
> Will using an UPS "compatible with inverter/generator" solve this problem?
> Is UPS claiming "compatible with generator" also compatible with Inverter
> ...





If I was at your place I wouldn't buy a new Inverter. I will do some trials before taking this decision. Firstly I couldn't figure out what are the compatibility issues, my inverter is couple of year old and the UPS is 10-15 yrs old till date they are functioning normally. Thus, I cannot buy this theory, and what are they trying to prove by promoting product with punch line like “Compatible with inverter/generators” etc, Do not fall in this trap, these are new dimensions of marketing tactics !   Even a layman knows that the UPS main function is to switch on immediately during power failure and use its OWN back up batteries NOT inverters batteries. Thus the UPS is not in anyway dependent on the inverter. It takes UPS 5-10 Milliseconds to change over, and inverter switch timing is 500 millisecond, which is much higher than ups. When there is power outage the inverter is the last one to analyze power outage before that ups has already done its job.  The inverter provides back up to UPS later on. 

You can try the following:-

1) Connect your present UPS DIRECTLY to main supply (Do not connect to inverter point !) and check its functioning. Lets see if it keep your pc stable. 

2) Was your UPS providing proper back up in the past ? When the battery was new. If yes, then the UPS battery is not able to handle 300+ watts back up instantly for your pc because there service life cycle is nearly ending. 

3) See if your inverter has UPS mode (watch the back of the inverter if you can find a small change over switch for "Inverter" and "UPS" mode). If not then you need to buy a inverter which has a UPS mode. Nowadays, those inverter are called as 'Home UPS'. Su-kam Falcon has this mode but mine is 2-3 yrs old now the new models have much better Home UPS features. They switch over faster like small UPS and don’t worry they provide refined electric supply like UPS. But please go for Pure Sine Wave only otherwise your computer may get faulty. If you buy then you DO NOT need to connect the small UPS to the computer. Connect the computer directly to the inverter line in while keeping the inverter in "UPS mode" and it will do the job of the UPS. There is only one concern which I am facing, you can read in my above post. I am afraid if you too share the same situation. I have low voltage problem in my area. When the power dipped below 185 volts the inverter stops charging the batteries and it goes on back up mode, because in ‘UPS mode’ the inverter needs above 185 volts to keep charging the battery. If that voltage remains constantly lower than 185 Volts, it will stop charging the batteries and will go on back up mode (using battery power) and the battery would get deeply discharged. For this I have inquired from engineer I need to connect a automatic voltage corrector (4 kva which we use for Air Conditioner) between main supply and inverter’s  Ac input for maintaining constant voltage. 

Note: For you it may be unnecessary expense just in case your area has low voltage power supply ie (less than 185 volt) then the sukam or any other inverter would not charge the battery in UPS mode (although it will charge okay when kept in Inverter mode) but this won't provide you any benefit of UPS. Mine is an old inverter, thus I can invest and install a voltage corrector.

4) I feel before investing in UPS if you can borrow the APC Ups from your father and use it for at least a week (as you should see its performance in power outage NOT by switching off the main supply) and check if it solves your purpose only then invest on it. And do one thing connect your numeric ups to your father desktop and see if it works okay there. 

Verdict:
-If you have low voltage issue then do not buy new inverter with “home UPS” feature. 
-If the borrowed APC ups is working okay then buy APC ups (no need to buy inverter). But first examine the performance of your old UPS after connecting to directly to main lines (ie not on inverter point)
-If even the APC ups is not providing back up then the problem is somewhere else. 
First try this and then let me know the results (you can send me a private message). There are other reasons too, which cause the switch over delays in UPS.


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## vickramperumal (Jul 3, 2012)

Thanks for your valuable inputs arayman.

I tested with the "Regulated UPS" mode in my luminous UPS and experienced the same 

problem (My computer reboots). 

As I have mentioned earlier my UPS can give stable backup for 20 - 30 seconds and I have 

reconfirmed the same on your advice.

My UPS was working fine before.

The option to test with my fathers APC is on the cards. Will update the community once 

its done.

After a detailed internet research, I assume the incompatibility of many UPS with 

inverter (reboot during switch over from mains to inverter) may be due to  the input 

frequency (usually 50 Hz) the UPS will / can accept. If you note the models mentioned 

compatible with generators (Autosave Nirantar UPS - 630 - has input frequency specified as "40Hz - No Limit Generator-input Setting)" has greater tolerance / acceptance range to input voltage frequency . 

I had a technical chat with the customer care representative of both APC and SU-KAM. The take home message from these conversations are

No pure sine wave UPS in real life conditions provides the same quality as grid power

Their frequencies are highly variable

Its always advisable to run your computer UPS in Main power and not in inverter power
Running computer in inverter power may damage your SMPS.



You can learn a lot from these below mentioned websites.
Ensuring Generator and UPS Compatibility | Contractor content from Electrical Construction and Maintenance (EC and M) Magazine
UPS vs Generator Problem Solved

Thanks to the dpreview form.
Running a UPS on generator power: PC Talk Forum: Digital Photography Review


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## arayman (Jul 6, 2012)

vickramperumal said:


> Thanks for your valuable inputs arayman.
> 
> I tested with the "Regulated UPS" mode in my luminous UPS and experienced the same
> 
> ...



1) Bye Pass the old UPS and connect your PC DIRECTLY to Inverter point (without computer UPS !) by keeping the inverter in "regulated ups" mode and observe for re-boot.

2) Firstly, connect the APC to inverter point, verify re-boot and then connect it on Main line (non-inverter point) and check its functioning in both the cases. (Note when you connect the APC to inverter output, the inverter should be kept on "inverter mode" not Regulated ups mode !)

Other reason which may cause re-boot:-
- Faulty or Cheap SMPS (power supply) is also one of the reason of re-boot. Hope you did not change the PSU of your pc lately. 
-Improper earthing of main line can also cause re-boot. 
-Try changing the electric phase (if you are having 3 phase connection). 
- Verify if lately your street transformer has not been changed or rectified by electricity dept. They sometimes change the behavior of current flow.


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## vickramperumal (Jul 8, 2012)

The point you mention "Improper earthing of main line can also cause re-boot" is interesting. As I had done another experiment in the past assuming that there is incompatibility between UPS and Inverter. I made a separate socket for the computer which is not supported by the inverter current but only by the grid current. To achieve the same the wires for the new socket (L, N & G) was extended through parallel connection from another power plug.  Now what happens is, when the power from mains is available there is no issue. But when I try to switch off the main manually and force the inverter (to check if all is well), the inverter drips and there is line – ground reversal in all sockets of the house (indicated by the spike buster). All electrical equipments connected to the Mains power (devoid of Inverter power during current cuts e.g., washing machine, TV extension chord that have a LED indicator) have their "power on" indicator glow. But they won’t work.  The same does not happen when the main are off due to actual power failure from grid. This problem did not exist before the fabrication of the extension box. So i was forced to remove the extension bo. now I have no problem. The electrician who did the connection was also not able to figure out the issue. i read in some form that " two neutrals cannot be screwed to a single screw". Is it true.


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